Preferred Language
Articles
/
jeasiq-287
Robust Estimations for power Spectrum in ARMA(1,1) Model Simulation Study
...Show More Authors

Simulation Study

 

Abstract :

Robust statistics Known as, Resistance to mistakes resulting of the deviation of Check hypotheses of statistical properties ( Adjacent Unbiased  , The Efficiency of data taken from a wide range of probability distributions follow a normal distribution or a mixture of other distributions with different standard deviations.

 power spectrum function lead to, President role in the analysis of Stationary random processes, organized according to time, may be discrete random variables or continuous. Measuring  its total capacity as frequency function.

Estimation methods Share with the concept of nonparametric in the absence of a model with clearly defined parameters (Free distribution) part with the distributed according to the Normal distribution, while the other part is unknown distribution, and thus it became the distribution of tainted its parameters is  unknown, so it can be considered the Robust Methods is the highest level in grades nonparametric methods which is will be based on the conversion calculable test to a Standard formula Conducted by the convergence operations.

The aim of the Search finding the best estimator of Power spectrum With the mixed ARMA (1,1) model for time series follow a Normal distribution. By Using Simulation experiments, on samples [n=50,100,150,200,250],and Different virtual values for و θ . It has been Showen  in tables 1,2,3 The Obvious difference between all the initial default values and generated values , Which may give results far from the real system results.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Sep 01 2014
Journal Name
Al-khwarizmi Engineering Journal
Experimental Performance of a Finned-tube Silica Gel Adsorption Chiller for Air-Conditioning Application
...Show More Authors

This work presents the construction of a test apparatus for air-conditioning application that is flexible in changing a scaled down adsorbent bed modules. To improve the heat and mass transfer performance of the adsorbent bed, a finned-tube of the adsorbent bed heat exchanger was used. The results show that the specific cooling power (SCP) and the coefficient of performance (COP) are 163 W/kg and 0.16, respectively, when the cycle time is 40 min, the hot water temperature is 90oC, the cooling water temperature is 30oC and the evaporative water temperature is 11.4oC.

View Publication Preview PDF
Publication Date
Sun Dec 01 2019
Journal Name
Journal Of Economics And Administrative Sciences
Use Generalized Pareto Survival Models to Estimation Optimal Survival Time for Myocardial Infarction Patients
...Show More Authors

The survival analysis is one of the modern methods of analysis that is based on the fact that the dependent variable represents time until the event concerned in the study. There are many survival models that deal with the impact of explanatory factors on the likelihood of survival, including the models proposed by the world, David Cox, one of the most important and common models of survival, where it consists of two functions, one of which is a parametric function that does not depend on the survival time and the other a nonparametric function that depends on times of survival, which the Cox model is defined as a semi parametric model, The set of parametric models that depend on the time-to-event distribution parameters such as

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Sep 01 2022
Journal Name
Iraqi Journal Of Physics
X-Ray Emission Spectroscopy Analysis for Near-Asteroid Belt of Atmospheric of the Comets
...Show More Authors

         According to Chandra Survey Observatory Near-Asteroid Belt Comets, the solar wind's contact with the comet produces a variety of spectral characteristics. The study of X-ray spectra produced by charge exchange is presented here. The spectrum of a comet can reveal a lot about its composition. This study has concentrated on the elemental abundance in six different comets, including 17P/Holmes, C/1999T1, C/2013A1, 9p/Temple1, and 103p/Hartley2 (NEAT). Numerous aspects of the comet's dynamics allow it to behave in a unique manner as it gets closer to the Near-Asteroid Belt. These characteristics are being examined, and some studies are still ongoing. The computations allow us to observe, for instance, how the composition of

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
On A Modified SP-Iterative Scheme for Approximating Fixed Point of A Contraction Mapping
...Show More Authors

In this paper, we will show that the Modified SP iteration can be used to approximate fixed point of contraction mappings under certain condition. Also, we show that this iteration method is faster than Mann, Ishikawa, Noor, SP, CR, Karahan iteration methods. Furthermore, by using the same condition, we shown that the Picard S- iteration method converges faster than Modified SP iteration and hence also faster than all Mann, Ishikawa, Noor, SP, CR, Karahan iteration methods. Finally, a data dependence result is proven for fixed point of contraction mappings with the help of the Modified SP iteration process.

View Publication Preview PDF
Publication Date
Fri Jan 26 2024
Journal Name
Iraqi Journal Of Science
Longitudinal and Transverse Electron Scattering Form Factors for 13C Nucleus with Core-Polarization Effects
...Show More Authors

Inelastic electron scattering have been studied for (3.68 )
2
1
2
3
MeV

,
(7.55 )
2
1
2
5
MeV

(15.11 )
2
3
2
3
MeV

states in the 13C nucleus. 4He is considered as an inert core with
nine nucleons out of it (the model space of nucleus). Form factors are calculated by
using Cohen-Kurath interaction for 1p-shell model space with Modified Surface
Delta Interaction (MSDI) as a residual interaction for higher configuration. The
study of core-polarization effects on the form factors is based on microscopic
theory, which combines shell model wave functions and configurations with higher
energy as the first order perturbation. The radial wave functions

... Show More
View Publication Preview PDF
Publication Date
Thu Feb 10 2022
Journal Name
Iraqi Journal Of Science
Determination of optimum conditions for xylanase production by Aspergillus niger using solid state fermentation
...Show More Authors

Aspergillus niger is one of the most important filamentous fungi that used in the fermentation industry. Aspergillus niger isolate was cultured on potato-dextrose agar (PDA) for activation, and the optimum conditions for xylanase production from this local isolate were studied by solid state fermentation, using a medium composed of wheat bran moisten with corn steep liquor at ratio 1:0.5 (v:w) at initial pH 5.5, inoc-ulated with 1.6 × 106 spores/ml, and incubated at 30ᵒC for 5 days.

View Publication Preview PDF
Publication Date
Tue Jan 30 2018
Journal Name
Iraqi Journal Of Science
Evaluation of Orbital Maneuvers for Transition from Low Earth Orbit to Geostationary Earth Orbit
...Show More Authors

The transition from low Earth orbit 200-1500 (km) to geostationary Earth orbit 42162 (km) was studied in this work by many methods of transfer. The delta-v requirement (Δv), the time of flight (Δt), the mass ratio of propellant consume (Δm/m) and total mass was calculated for many values altitude in the same plane also when the plane is change. The results from work show that (Δv) that required for transfer when the plane of orbit change is large than (Δv) required when the transfer in coplanar maneuvers while the bi-elliptical transfer method need time of transfer longer than a Hohmann transfer method. The most energy efficiency was determined when the transfer in coaxial between elliptical orbits

... Show More
View Publication Preview PDF
Publication Date
Wed Aug 30 2023
Journal Name
Al-kindy College Medical Journal
‘Peacock tail’ Clipping Technique for a Giant Middle Cerebral Artery Aneurysm: A Technical Note
...Show More Authors

Background: Giant middle cerebral artery (MCA) aneurysms are surgically challenging lesions. Because of the complexity and variability of these aneurysms, a customized surgical technique is often needed for each case. In this article, we present a modified clip reconstruction technique of a ruptured complex giant partially thrombosed middle cerebral artery aneurysm.

Case description: The aneurysm was exposed using the pterional approach. Following proximal control, the aneurysm sac was decompressed. Then, we applied permanent clips to reconstruct the aneurysm neck. The configuration of the aneurysm mandated a tailored clipping pattern to account for resi

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Sun Sep 01 2013
Journal Name
Baghdad Science Journal
Synthesis of substituted (oxazepine, Diazepine, tetrazde) via Schiff Bases for 2- Aminobenzo Thaizole Derivatives
...Show More Authors

This work includs synthesis of several Schiff bases by condensation of 6- methoxy – 2- amino benzothiazole with some aldehydes and ketones (2- hydroxyl benzaldehyde, 4- hydroxyl benzaldehyde, 4- N,N –dimethy amino acetophenone, benzophenone) to abtain schiff bases (1-5). These schiff bases were found to react with phthalate anhydride to give oxazepine derivatives (6-10) that were reacted with primary aromatic amines to give Diazepine derivatives (11-15). Besides, we prepared new tetrazole derivatives (16-20) from the reaction of the prepared Schiff bases with sodium azide in the prepared compounds that were characterized by physical properties, FT-IR and some of the 1H-NMR and 13C –NMR spectroscopy.

View Publication Preview PDF
Crossref
Publication Date
Sun Dec 05 2021
Journal Name
Iraqi Journal Of Science
Climatic Analysis and Climatic Water Balance Determination for Al- Yusufiyah Area, Southern Baghdad, Iraq
...Show More Authors

The Climatic parameters for the years (1985-2015) were collected from Baghdad
meteorological station and then were applied to evaluate the climatic conditions for
the Al-Yusufyiah area south Baghdad. The total annual rainfall is (119.65 mm),
while the total annual evaporation is (3201.7 mm), relative humidity is (43.62%),
sunshine (8.76 h/day), temperature (23.28 C◦) and wind speed (3.06 m/sec). Climate
of the study area is described as an arid according to classification of (Kettaneh and
Gangopadhyaya, 1974), (Mather, 1973), and (Al-Kubaisi, 2004). Mean monthly
water surplus for the period (1985-2015) was recorded in the study area about (4.7
mm) in November, (11.67 mm) in December, (20.56 mm) in January and (6

... Show More
View Publication Preview PDF