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
The aim of the research is to identify the cognitive method (rigidity flexibility) of third-stage students in the collage of Physical Education and Sports Sciences at The University of Baghdad, as well as to recognize the impact of using the McCarthy model in learning some of skills in gymnastics, as well as to identify the best groups in learning skills, the experimental curriculum was used to design equal groups with pre test and post test and the research community was identified by third-stage students in academic year (2020-2021), the subject was randomly selected two divisions after which the measure of cognitive method was distributed to the sample, so the subject (32) students were distributed in four groups, and which the pre te
... Show Moreأولاً: مشكلة البحث:
على الرغم من أن كل شخص هو كائن متفرد بحد ذاته ، إلا أن هناك تشابهات مشتركة بين كثير من الناس ، وتشكل هذه التشابهات أنماطآ شخصية يهدف علم النفس إلى دراستها وفهمها.
وقد حاول علماء النفس والمنظرون في مجال الشخصية بناء أنظمة نظرية لتغطية التباين الواسع بين الأفراد في السلوك ضمن المواقف المختلفة. وهدفت جهودهم إلى فهم الدافعية البشرية ، والسلوك عن طريق عملية النمو
... Show MoreThe present study aims to develop and apply the unrealistic optimism scale among high school students. The researcher has designed a scale of (38) paragraphs to measure the unrealistic optimism. A sample of (200) male and female students were chosen randomly to collect the needed data. The study found that the unrealistic scale of optimism has good psychometric characteristics. The research sample has a high level of التفاؤل غير الواقعي لدى عينة البحث unrealistic optimism. There is a statistically significant difference between male and female in the unrealistic optimism in favor of the male students. Finally, there is a statistically significant difference between students in the fourth and sixth gra
... Show Moreصار لزاماً علينا بيان مفهوم المعنى الحقيقي للجهاد وبيان أفضل أنواعه ورتبه وتحديداً الجهاد الكفائي بين النظرية والتطبيق من حيث معناه العام وبجوانبه الفكرية والاجتماعية , والسياسية ,والاقتصادية , وإيماناً منّا بانتفاضة المرجعية العليا في إعلانها الجهاد الكفائي ضد العصابات الارهابية التي استباحت الدين والوطن فكانت بالفعل الهام إلهي جسد أروع مبادئ الاسلام في التضحية والدفاع عن الدين ومقدساته , وانبل القيم الا
... Show MoreAttention is one of the mental processes of knowledge that play an important role in the life of the individual in general and the child's life, in particular, the child relates to the external environment through its interaction with it, to achieve the adjustment with his environment and harmony with his community.
Much ness and multiplicity of information sources make the child need to scan and exploration to provide the appropriate response by handling sensory stimuli involving the discovery of stimulus and receive it by sensory devices then pay attention to it and realizing and storing it in memory and restoring it in the next positio
... Show MoreThe aim of the present research is to construct a model to evaluate the software engineering subject in the third grade department of Computing, in colleges of education. Then, evaluating the software Engineering subject from the view point of staff members by applying the constructed model, and in order to achieve the second aim of the present research the researcher has to find answers to the following questions:- 1. What is the presence of the proposed evaluating model fields, which was prepared by the researcher for the third grade Soft Ware Engineering subject from the view point of staff members? 2. What is the presence of the items for the proposed evaluating model, which was prepared by the researcher for the third grade Soft War
... Show MoreAmong all the common mechanical transmission elements, gears still playing the most dominant role especially in the heavy duty works offering extraordinary performance under extreme conditions and that the cause behind the extensive researches concentrating on the enhancement of its durability to do its job as well as possible. Contact stress distribution within the teeth domain is considered as one of the most effective parameters characterizing gear life, performance, efficiency, and application so that it has been well sought for formal gear profiles and paid a lot of attention for moderate tooth shapes. The aim of this work is to investigate the effect of pressure angle, speed ratio, and correction factor on the maxi
... Show MoreThe effect of air injection device on the performance of airlift pump used for water pumping has been studied numerically and experimentally. An airlift pump of dimensions 42mm diameter and 2200 mm length with conventional and modified air injection device was considered. A modification on conventional injection device (normal air-jacket type) was carried out by changing injection angle from 90 (for conventional) to 22.5 (for modified). Continuity and Navier-Stokes equations in turbulent regime with an appropriate two-phase flow model (VOF) and turbulent model ( ) in two dimensions axisymmetry flow were formulated and solved by using the known package FLUENT version (14.5). The numerical and experimental investiga
... Show MoreEpoxy (EP) – Silica (SiO2) composites are well known composites used in microelectronic industry . So it is important to study their dielectric behavior under different conditions such as
the presence carbon black (UV absorber) and immersion in the water for 30 days .
Dielectric properties were calculated over the frequency range 102 – 106 Hz for epoxy composites with different weight % of micrometer 1.5μm SiO2 particles (60%, 65% and 70wt%) modified with 0.5wt% silane coupling agent to improve adhesion between EP and SiO2 phases .