Preferred Language
Articles
/
jeasiq-927
Eatimation Availability Function Through Determination The Optimal Imperfect Preventive Maintenance Period By using Simulation
...Show More Authors

This paper deals with the modeling of a preventive maintenance strategy applied to a single-unit system subject to random failures.

According to this policy, the system is subjected to imperfect periodic preventive maintenance restoring it to ‘as good as new’ with probability

p and leaving it at state ‘as bad as old’ with probability q. Imperfect repairs are performed following failures occurring between consecutive

preventive maintenance actions, i.e the times between failures follow a decreasing quasi-renewal process with parameter a. Considering the

average durations of the preventive and corrective maintenance actions as well as their respective efficiency extents, a mathematical model

is developed in order to study the evolution of the system stationary availability and determine the optimal PM period which maximizes

  1. The modeling of the imperfection of the corrective maintenance actions requires the knowledge of the quasi-renewal function when times to first failure follow a Weibull Distribution.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Apr 01 2022
Journal Name
Baghdad Science Journal
An Evolutionary Algorithm for Solving Academic Courses Timetable Scheduling Problem
...Show More Authors

Scheduling Timetables for courses in the big departments in the universities is a very hard problem and is often be solved by many previous works although results are partially optimal. This work implements the principle of an evolutionary algorithm by using genetic theories to solve the timetabling problem to get a random and full optimal timetable with the ability to generate a multi-solution timetable for each stage in the collage. The major idea is to generate course timetables automatically while discovering the area of constraints to get an optimal and flexible schedule with no redundancy through the change of a viable course timetable. The main contribution in this work is indicated by increasing the flexibility of generating opti

... Show More
View Publication Preview PDF
Scopus (8)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Sat Oct 28 2023
Journal Name
Baghdad Science Journal
Quantum Theory of Atom in Molecules Investigation Trinuclear Ruthenium: DFT Approach
...Show More Authors

The topological indices of the "[(µ3-2, 5-dioxyocyclohexylidene)-bis ((2-hydrido)-nonacarbonyltriruthenium]” were studied within the quantum theory of atoms in the molecule (QTAIM), clusters are
analyzed using the density functional theory (DFT). The estimated topological variables accord with prior
descriptions of comparable transition metal complexes. The Quantum Theory of Atom, in molecules
investigation of the bridging core component, Ru3H2, revealed critical binding points (chemical bonding)
between Ru (1) and Ru (2) and Ru (3). Consequently, delocalization index for this non-bonding interaction
was calculated in the core of Ru3H2, the interaction is of the (5centre–5electron) class.

View Publication Preview PDF
Scopus Crossref
Publication Date
Fri Mar 01 2024
Journal Name
Baghdad Science Journal
Best approximation in b-modular spaces
...Show More Authors

In this paper, some basic notions and facts in the b-modular space similar to those in the modular spaces as a type of generalization are given.  For example, concepts of convergence, best approximate, uniformly convexity etc. And then, two results about relation between semi compactness and approximation are proved which are used to prove a theorem on the existence of best approximation for a semi-compact subset of b-modular space.

View Publication Preview PDF
Scopus Crossref
Publication Date
Tue Jul 01 2014
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Immunohistochemical study of bone marrow angiogenesis in multiple myeloma and its correlation with clinicopathological factors
...Show More Authors

Background: In recent years, bone marrow angiogenesis was reported to be involved in the pathogenesis and progression of certain hematological malignancies like multiple myeloma, leukemias, and lymphomas. Recent studies have suggested that bone marrow angiogenesis plays an important role in the pathogenesis and prognosis of multiple myeloma.
Objectives: at the present study, bone marrow angiogenesis in multiple myeloma was examined using immunohistochemical staining for CD34, and correlated with various pathological and clinical parameters.
Patients and methods: This is a retrospective study; where by archival paraffin-embedded tissue blocks along with the clinical and hematological records of fifty-two patients with multiple myelo

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Oct 01 2014
Journal Name
Journal Of The Faculty Of Medicine Baghdad
CA19-9 and CK immunohistochemical expression in pancreatic and ampulla of vater carcinomas (A clinicopathological study
...Show More Authors

Background: Pancreatic carcinoma is one the most lethal malignancies and the Prognosis for patients with locally advanced or metastatic disease is poor. The 5-year survival rate is about 4%, which is the lowest of any cancer and median survival is 6 months. The high mortality rate is largely due to the typically advanced stage of the cancer at the time of diagnosis and treatment. Resection is the only current treatment resulting in cure for pancreatic carcinoma. However, due to the initiation and progression of this cancer without symptoms, only about 10% to 15% of patients present with localized disease amenable to potentially curative resection. Chemotherapy increases survival and up to date, the use of pallia

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Oct 28 2023
Journal Name
Baghdad Science Journal
Generalized Left Derivations with Identities on Near-Rings
...Show More Authors

In this paper, new concepts which are called: left derivations and generalized left derivations in nearrings have been defined. Furthermore, the commutativity of the 3-prime near-ring which involves some
algebraic identities on generalized left derivation has been studied.

View Publication Preview PDF
Scopus Crossref
Publication Date
Sun Sep 01 2019
Journal Name
Baghdad Science Journal
Common Fixed Point of a Finite-step Iteration Algorithm Under Total Asymptotically Quasi-nonexpansive Maps
...Show More Authors

      Throughout this paper, a generic iteration algorithm for a finite family of total asymptotically quasi-nonexpansive maps in uniformly convex Banach space is suggested. As well as weak / strong convergence theorems of this algorithm to a common fixed point are established. Finally, illustrative numerical example by using Matlab is presented.

View Publication Preview PDF
Scopus (13)
Crossref (3)
Scopus Clarivate Crossref
Publication Date
Tue Jun 01 2010
Journal Name
Journal Of Economics And Administrative Sciences
مقارنة طرائق تقدير معلمات دالة الشدة لعمليات بواسون غير المتجانسةمقارنة طرائق تقدير معلمات دالة الشدة لعمليات بواسون غير المتجانسةمقارنة طرائق تقدير معلمات دالة الشدة لعمليات بواسون غير المتجانسة
...Show More Authors

This research deals with parameters estimation methods for the intensity function of non homogeneous poisson processes , it aims to estimate parameters of this function throughout three methods which are maximum likelihood method , moment method and shurnkage method using simulation method.

In order to achive the best method, several assumed values for parameters of intensity function have been adopted  using sample size of 
(14, 25, 50, 100) .Results of estimation showed that the estimation over the estimation method , of maximum likelihood and moment .

  This estimation gain the least mean of squares error for the above samples .

&nbs

... Show More
View Publication Preview PDF
Crossref
Publication Date
Wed Feb 01 2023
Journal Name
Baghdad Science Journal
Influence of Nanosilica on Solvent Deasphalting for Upgrading Iraqi Heavy Crude Oil
...Show More Authors

In this study, the upgrading of Iraqi heavy crude oil was achieved utilizing the solvent deasphalting approach (SDA) and enhanced solvent deasphalting (e-SDA) by adding Nanosilica (NS). The NS was synthesized from local sand. The XRD result, referred to as the amorphous phase, has a wide peak at 2Θ= (22 - 23º) The inclusion of hydrogen-bonded silanol groups (Si–O–H) and siloxane groups (Si–O–Si) in the FTIR spectra. The SDA process was handled using n-pentane solvent at various solvent to oil ratios (SOR) (4-16/1ml/g), room and reflux temperature, and 0.5 h mixing time. In the e-SDA process, various fractions of the NS (1–7 wt.%) have been utilized with 61 nm particle size and 560.86 m²/g surface area in the presence of 12 m

... Show More
View Publication Preview PDF
Scopus (4)
Crossref (5)
Scopus Clarivate Crossref
Publication Date
Mon Jul 01 2013
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Surgery for wilms' tumor, Does Preoperative Chemotherapy Ease its Surgical Procedure?
...Show More Authors

Background: The optimal timing of surgery for Wilms' tumor has been debated for many years. It appears dubious whether surgical ease or per operative complications consistently improved after preoperative chemotherapy.

Materials and Methods: This is a cross section study ,the sample collected from January  2009  to November  2012 .Thirty four  patients were selected after informed consent . Patients aged between 10 months and 5 years who were newly diagnosed with Wilms' tumors. including (17)  patients  with unilateral wilms tumors received immediate nephrectomy without preoperative chemotherapy according to the National Wilms' Tumor Study Group protocol  and (1

... Show More
View Publication Preview PDF
Crossref