Limit and License

Discussion of the past and future of architecture and energy, with Barnabas Calde

KNOWLEDGE DISCOVERY IN ARTIFICIAL NEURAL NETWORKS AND REGRESSION MODELS

In this paper, Artificial Neural Networks (ANN) and Regression Analysis models were considered to determine which ofthem performs better. Prediction was done using one hidden layer and three processing elements in the ANN model.Furthermore, prediction was done using regression analysis. The parameters of regression model were estimated using LeastSquare method. To determine the better prediction, mean square errors (MSE) attached to ANN and regression models wereused. Seven real series were fitted and predicted with in both models. It was found out that the mean square error attached to ANNmodel was smaller than regression model which made ANN a better model in prediction.Keywords: Artificial Neural Networks, Regression, Least Square, Processing Element, Hidden Layer, Mean Square Error.

Type Iax SNe as a few-parameter family

We present direct spectroscopic modeling of five Type Iax supernovae (SNe) with the one dimensional Monte Carlo radiative transfer code TARDIS. The abundance tomography technique is used to map the chemical structure and physical properties of the SN atmosphere. Through via fitting of multiple spectral epochs with self-consistent ejecta models, we can then constrain the location of some elements within the ejecta. The synthetic spectra of the best-fit models are able to reproduce the flux continuum and the main absorption features in the whole sample. We find that the mass fractions of IGEs and IMEs show a decreasing trend toward the outer regions of the atmospheres using density profiles similar to those of deflagration models in the literature. Oxygen is the only element, which could be dominant at higher velocities. The stratified abundance structure contradicts the well-mixed chemical profiles predicted by pure deflagration models. Based on the derived densities and abundances, a template model atmosphere is created for the SN Iax class and compared to the observed spectra. Free parameters are the scaling of the density profile, the velocity shift of the abundance template, and the peak luminosity. The results of this test support the idea that all SNe Iax can be described by a similar internal structure, which argues for a common origin of this class of explosions.Comment: 21 pages, 7 tables, 16 figures, accepted by MNRA

Calculation of the Hidden Symmetry Operator for a \cP\cT-Symmetric Square Well

It has been shown that a Hamiltonian with an unbroken \cP\cT symmetry also possesses a hidden symmetry that is represented by the linear operator \cC. This symmetry operator \cC guarantees that the Hamiltonian acts on a Hilbert space with an inner product that is both positive definite and conserved in time, thereby ensuring that the Hamiltonian can be used to define a unitary theory of quantum mechanics. In this paper it is shown how to construct the operator \cC for the \cP\cT-symmetric square well using perturbative techniques.Comment: 10 pages, 2 figure

The Effect of Missing Data Treatment on Mantel-Haenszel DIF Detection

Most implementations of the Mantel-Haenszel differential item functioning procedure delete records with missing responses or replace missing responses with scores of 0. These treatments of missing data make strong assumptions about the causes of the missing data. Such assumptions may be particularly problematic when groups differ in their patterns of nonresponse. Using both real data from Ontario students taking the English- and French-language versions of two large-scale assessments and simulated data, this study compared the Mantel-Haenszel DIF indices produced using a total score or a proportion score as matching variables and treating missing data by listwise deletion, analysiswise deletion, or scoring missing data as incorrect. The results suggest that when many responses are missing, differential nonresponse rates may be a source of DIF. La plupart des mises en oeuvre de la méthode du fonctionnement différentiel des items de MantelHaenszel suppriment les observations ayant des réponses qui manquent ou bien elles remplacent les réponses manquantes par un 0. Ces façons de traiter l'information manquante repose sur des hypothèses quant aux causes des lacunes, hypothèses qui pourraient s'avérer particulièrement inquiétantes quand l'absence de réponse chez les différents groupes suit un schéma distinct. En nous appuyant tant sur des données réelles d'élèves de l'Ontario ayant passé les versions en anglais et en français de deux évaluations à grande échelle, que sur des données simulées, nous avons comparé les indices de la méthode du fonctionnement différentiel des items de MantelHaenszel produits par l'emploi d'un score total ou d'un score de proportion comme variables appariées et en traitant les données manquantes de trois façons : suppression de toutes les observations comportant au moins une valeur manquante; calcul de la corrélation pour chaque couple de variables à partir des données disponibles; ou considération des données manquantes comme des erreurs. Les résultats portent à croire que lorsqu'il manque plusieurs réponses, les taux différentiels d'absence de réponse peuvent constituer une source de fonctionnement différentiel des items

Tinjauan Pengembangan Landasan Pacu Bandar Udara Kasiguncu Kabupaten Poso

Means of airport for landing and take off of aircraft is runway. This writing to determine the direction of runway according to aircraft that serviced, geometric requirements of existingrunway conditions in 2011 and the development of phase II stage 2 in 2030 and runway pavement thickness existing conditions in 2011 and the development of phase II stage 2 in 2030. Method that used to determine the direction of the runway using the wind rose and for geometric runway using the ICAO and FAA as well as for runway pavement thickness using the FAA.From the wind analysis result using the wind rose, the direction of the existing runway 03-21 can be used safely. From the calculation result of the geometric condition of existing runway length obtained in 2011 by ICAO runway at for the Fokker F-28 aircraft while the width of the runway by ICAO and FAA at 30,48 m. The condition of the existing runway has a runway length 1.617 m and a width 30 m, so that the runway has been unable to serve the aircraft.For the conditions of the development of phase II stage 2 in 2030 acquired by the FAA runway length at 2.070 m and width 30,48 m while the length of the runway by ICAO at 2.704 m and a width 45,72 m. Conditions runway geometric phase II development stage 2 has a length 2.100 m and a width 45 m, so the runway is capable of servicing Boeing 737-300 aircraft safely compared with FAA planning method. From the calculation result of runway pavement thickness existing conditions in 2011 earned a total pavement thickness is 38 cm with aircraft plan Xian MA-60. Condition of existing runway has a total pavement thickness is 87 cm so that the Xian MA-60 aircraft can be served safely. For the conditions of the development of phase II stage 2 obtained after the equivalent total pavement thickness is 69,5 m for model 1 and 68,8 cm for the model 2 with aircraft plan Boeing 737-300. Conditions runway development phase II stage 2 has a totalpavement thickness after the equivalent is 77,5 cm, so the Boeing 737-300 aircraft can be served safely

Evaluation of Sediment Yield Predicting Models of Ghana

Fluvial sediment transport data is a very important data for effective water resource management. However, acquiring this data is expensive and tedious hence sediment yield modeling has become an alternative approach in estimating river sediment yields. In Ghana, several sediment yield predicting models have been developed to estimate the sediment yields of ungauged rivers including the Pra River Basin. In this paper, 10 months sediment yield data of the Pra River Basin was used to evaluate the existing sediment yield predicting models of Ghana. A regression analysis between predicted sediment yield data derived from the models and the observed suspended sediment yields of the Pra Basin was done to determine the extent of estimation of observed sediment yields. The prediction of suspended sediment yield was done for 4 out of 5 existing sediment yield predicting models in Ghana. There were variations in sediment yield between observed and predicted suspended sediments. All predicted sediment yields were lower than observed data except for equation 3 where the results were mixed. All models were found to be good estimators of fluvial sediments with the best model being equation 4. Sediment yield tends to increase with drainage basin area.