Preferred Language
Articles
/
bsj-7489
Building a Sustainable GARCH Model to Forecast Rubber Price: Modified Huber Weighting Function Approach
...Show More Authors

The unstable and uncertain nature of natural rubber prices makes them highly volatile and prone to outliers, which can have a significant impact on both modeling and forecasting. To tackle this issue, the author recommends a hybrid model that combines the autoregressive (AR) and Generalized Autoregressive Conditional Heteroscedasticity (GARCH) models. The model utilizes the Huber weighting function to ensure the forecast value of rubber prices remains sustainable even in the presence of outliers. The study aims to develop a sustainable model and forecast daily prices for a 12-day period by analyzing 2683 daily price data from Standard Malaysian Rubber Grade 20 (SMR 20) in Malaysia. The analysis incorporates two dispersion measurements (IQR/3 and Sn) and three levels of IO contamination 0%, 10%, and 20%. The results indicate that using the Huber weighting function with the IQR/3 measurement to build the AR(1)-GARCH(2,1) model leads to better sustainability. These findings have the potential to enhance the GARCH model by modifying the weighting function of the M-estimator

Scopus Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Mon Dec 25 2017
Journal Name
Oriental Journal Of Chemistry
Adsorption of 4-Chlorophenol from Aqueous Solution Onto Iraqi Bauxite and Surfactant–Modified Iraqi Bauxite: Equilibrium, Kinetic, and Thermodynamic Studies
...Show More Authors

View Publication
Scopus (4)
Crossref (1)
Scopus Crossref
Publication Date
Tue Dec 30 2014
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Removal of SO2 over Modified Activated Carbon in Fixed Bed Reactor: I, Effect of Metal Oxide Loadings and Acid Treatment
...Show More Authors

 

The removal of SO2 from simulated gas stream (SO2 + air) in a fixed bed reactor using Modified Activated Carbon (MAC) catalysts was investigated. All the experiments were conducted at atmospheric pressure, initial SO2 concentration of 2500 ppm and bed temperature of 90oC. MAC was prepared by loading a series of nickel and copper oxides 1, 3, 5, 7, and 10 w

... Show More
View Publication Preview PDF
Publication Date
Wed Dec 05 2018
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
X-Ray Fluorescence Determination of Trace Elements in Vitamin-Mineral Complexes and Medicinal Herbs Using Chemically Modified Polyurethane Foam Sorbents
...Show More Authors

In this paper we proposed the method of X-ray fluorescence (XRF) determination of some essential trace elements in medicinal herbs and vitamin-mineral complexes at the level of 100-101 mg/ml. To increase sensitivity and selectivity of the determination we simple and effective approach based on the extraction of metal ions from aqueous solutions with chemically modified polyurethane foam sorbents followed by direct XRF analysis. The conditions of sorption preconcentration of Co(II), Ni(II) and Zn(II) ions with modified sorbents were optimized. The proposed approach is used for the determination of trace elements in several kinds of medicinal herbs (coltsfoot leaves, nettle leaves and yarrow herb) and vitamin-mineral

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Mar 04 2008
Journal Name
Journal Of Baghdad College Of Dentistry
Twelve months clinical comparison between modified Widman flap with or without enamel matrix derivative for the treatment of infrabony defects
...Show More Authors

Publication Date
Tue Mar 27 2018
Journal Name
Mustansiria Dental Journal
The Effect of Modified Carisolv Gel on Surface Roughness of two Different Types of Ceramic Materials Using Light Polarizing Microscope
...Show More Authors

This in vitro study evaluated the influence of chemomechanical caries removal solution on the surface topography of metal-ceramic feldspar porcelain (MAJOR ceramic) and All-ceramic feldspar porcelain (Vita Alpha) using light polarizing microscope. Forty specimens of MAJOR ceramic and forty specimens of Vita Alpha ceramic of (12mm diameter & 3mm height) were prepared .All specimens were polished with silicon polishing burs, cleaned, autoglazed and stored in 37°C before exposure to Carisolv. Thirty specimens of each material randomly exposed to Carisolv gel for 5, 10 and 20 minutes respectively, other ten specimens were not, to act as control group. All specimens were subjected to surface roughness test by profilometer and evalua

... Show More
View Publication
Crossref
Publication Date
Tue Feb 03 2026
Journal Name
Journal Of Baghdad College Of Dentistry
The influence of adding of modified ZrO2-TiO2 nanoparticles on certain physical and mechanical properties of heat polymerized acrylic resin
...Show More Authors

Background: The mechanical and physical properties of Polymethyl methacrylate (PMMA) don’tfulfill the entire ideal requirements of denture base materials. The purpose of this study was to produce new modified polymer nanocomposite (PMMA /ZrO2-TiO2) andassess itsimpact strength, transverse strength and thermal conductivity in comparison to the conventionalheat polymerized acrylic resin. Materials and Methods: Both ZrO2 and TiO2nano fillers were silanized with TMSPM (trimethoxysilyl propyl methacrylate) silane coupling agent before beingdispersed by ultrasonication with the methylmethacrylate (monomer) and mixed with the polymer by means of 2% by weight in (1:1) ratio, 60 specimens were constructed by conventional water bath processing

... Show More
View Publication Preview PDF
Publication Date
Wed Nov 05 2025
Journal Name
Journal Of Oral Biology And Craniofacial Research
The effect of thermocycling on fracture resistance of zirconia crowns cemented with polylysine modified resin cements (Comparative in vitro study)
...Show More Authors

ABSTRACT Background: resin cement type and intraoral temperature fluctuations may affect the fracture performance of successful zirconia restorations. To fill this gap, the purpose of this study is to evaluate and compare the influence of thermocycling on fracture resistance and mode of failure of monolithic zirconia crowns luted with Rely X™ U200 and BreezeTMself-adhesive resin cements as well as imply the effect of adding 2 % of polylysine (PLS) to these cements. Materials: 64 maxillary premolars were milled out of zirconia blocks using CAD/CAM milling system. They were divided into four groups (n = 16) according to the cement type. Four different resin cements were used (RelyXTMU200, Breeze™, RelyX™ U200 with 2 % PLS

... Show More
View Publication
Scopus Crossref
Publication Date
Thu Apr 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Estimate the Partial Linear Model Using Wavelet and Kernel Smoothers
...Show More Authors

This article aims to estimate the partially linear model by using two methods, which are the Wavelet and Kernel Smoothers. Simulation experiments are used to study the small sample behavior depending on different functions, sample sizes, and variances. Results explained that the wavelet smoother is the best depending on the mean average squares error criterion for all cases that used.

 

 

View Publication Preview PDF
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
مجلة الدنانير
تأثير بناء المقدرات الجوهرية في إدارة الإيرادات الضريبية/ بحث تحليلي في الهيئة العامة للضرائب
...Show More Authors

هدف البحث الى بيان تأثير بناء المقدرات الجوهرية المتمثل ابعادها بـ (التعلم التنظيمي ، المرونة الاستراتيجية ، المقدرات التكنولوجية، رأس المال البشري) في ادارة الايرادات الضريبية المتمثلة ابعادها بـ (فاعلية الادارة الضريبية ، الكفاءة في العمل ، التشريعات الضريبية) وتم اعتماد الاستبانة كأداة رئيسة في جمع البيانات والمعلومات من العينة البالغ عددها (35) مبحوثاً ممن هم بموقع (مدير قسم ، وكيل مدير قسم، مسؤول شعبة) ف

... Show More
Preview PDF
Publication Date
Sun Apr 04 2010
Journal Name
Journal Of Educational And Psychological Researches
بناء مقياس معنى الحياة كما تدركه طالبة الجامعة على وفق Multidimensional Item Response Model
...Show More Authors

The undimensionality hypothesis which is item response theory depend it is unable in some of measurement situations because there are many dimensions which are affect of the response, so as the researches reached to expand this hypothesis to construct a new one which is multidimensional, and many of theories are pointed to the concept of meaning of life is multidimensionality, so this research aimed to construct the scale of meaning of life as the student's perception according with Multidimensional Item Response Model and this research adopt Wong's theory 1998 which point to the meaning of life consist of (7) dimensions. The research tool contains (49) items distributed at dimensions of meaning of life. Sample of statistical ana

... Show More
View Publication Preview PDF