Preferred Language
Articles
/
VoZ8soYBIXToZYAL47HT
Multi-Channel Distributed DSA Networks: Connectivity and Rendezvous Tradeoffs
...Show More Authors

In this paper, we investigate and characterize the effects of multi-channel and rendezvous protocols on the connectivity of dynamic spectrum access networks using percolation theory. In particular, we focus on the scenario where the secondary nodes have plenty of vacant channels to choose from a phenomenon which we define as channel abundance. To cope with the existence of multi-channel, we use two types of rendezvous protocols: naive ones which do not guarantee a common channel and advanced ones which do. We show that, with more channel abundance, even with the use of either type of rendezvous protocols, it becomes difficult for two nodes to agree on a common channel, thereby, potentially remaining invisible to each other. We model this invisibility as a Poisson thinning process and show that invisibility is even more pronounced with channel abundance. Following the disk graph model, we represent the multiple channels as parallel edges in a graph and build a multi-layered graph (MLG) in R2. In order to study the connectivity, we show how percolation occurs in the MLG by coupling it with a typical discrete percolation. Using a Boolean model and the MLG, we study both cases of primaries' absence and presence. For both cases, we define and characterize connectivity of the secondary network in terms of the available number of channels, deployment densities, number of simultaneous transmissions per node, and communication range. When primary users are absent, we derive the critical number of channels which maintains supercriticality of the secondary network. When primary users are present, we characterize and analyze the connectivity for all the regions: channel abundance, optimal, and channel deprivation. For each region we show the requirement and the outcome of using either type of rendezvous techniques. Moreover, we find the tradeoff between deployment-density versus rendezvous probability which results in a connected network. Our results can be used to decide on the goodness of any channel rendezvous algorithm by computing the expected resultant connectivity. They also provide a guideline for achieving connectivity using minimal resources.

Scopus Clarivate Crossref
Publication Date
Fri Dec 27 2024
Journal Name
Al–bahith Al–a'alami
News Coverage in the Iraqi Electronic Press for Internal Crises: (An Analytical Study of Al-Zaman and Al-Sabah Electronic Newspapers for the period from 1/ 3/ 2013 to 31/ 3/ 2013)
...Show More Authors

 

The research study focused on the need to clarify the relationship between the Websites of Iraqi Newspapers and their roles in covering the internal crises in Iraq. The selection of Iraqi websites for the newspapers Al-Zaman and Al-Sabah was adopted as one of the most important media with a wide audience; and as a model of hot news and continuous coverage of those sites since 2003 so far. As a result, this necessitated the emergence of new types of methods of editing and writing news stories related to Iraq.

Consequently, the enormous and rapidly changing amount of Iraq news, the process of preparing and creating news has become a complex industry

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Jan 01 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Measuring the relationship between the skills required for the labor market and the employment of graduates of community colleges in KSA: An applied study on a sample of faculty members at KKU
...Show More Authors

This study has aimed to measure the relationship between the skills required for the labor market and the employment of graduates of community colleges at King Khalid University. For gathering the required data, a questionnaire has been designed and distributed to the faculty members of community colleges at King Khalid University in a random sample method. The chosen sample size has covered (123) individuals. Questionnaire forms have been distributed and retrieved from (117) participants. Therefore, the estimated response has reached 95 % of the total sample size. The results of the study have shown that there is not any significant relationship between the skills which the graduates   acquire and the requirements of employmen

... Show More
View Publication Preview PDF
Publication Date
Thu Nov 01 2018
Journal Name
Journal Of Economics And Administrative Sciences
The research is based on a thesis not discussed: Test the strategy of the General Organization based on the model Wichler and Bakov A case study at the Iraqi Ministry of Interior
...Show More Authors

The study aimed at identifying the strategic gaps in the actual reality of the management of public organizations investigated to determine the strategy used based on the study model. The study relied on the variable of the general organization strategy in its dimensions (the general organization strategy, the organization's political strategy and the defense strategy of the organization) The sample of the study was (General Directorate of Traffic, Civil Status Directorate and Civil Defense Directorate), formations affiliated to the Ministry of the Interior, for the importance of the activity carried out by these public organizations by providing them In order to translate the answers into a quantitative expression in the analysi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sun Jul 24 2022
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Assessment of Total Procollagen Type 1 Intact N-terminal Propeptide, C-telopeptide of type 1 collagen, Bone Mineral Density and its Relationship to Body Mass Index in Men with Type 2 Diabetes
...Show More Authors

Background: Type 2 diabetes negatively affects the biochemical parameters of bone turnover more than obesity and is associated with an increased risk of osteoporosis and fragility fractures. Obesity and type 2 diabetes (T2DM) are linked to increased fracturing risk; however, the effect of obesity on diabetes-related bone deficit is unknown.

Objective: The goal of this research is to compare the indications, bone density, and bone turnover in T2DM men and a control group, and to investigate the effect of body mass index on bone turnover levels.

Subjects, Material and Method: This case-control study was conducted on 120 men whose ages were from 40 - 69 years. They were groupe

... Show More
View Publication Preview PDF
Crossref (1)
Crossref
Publication Date
Sat Mar 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Activating Financial Performance Measures On The Basis Of Value And Its Reflection On Companies Performance Under The Governance: An Applied Study On A sample Of Companies Listed In the Iraqi Stock Exchange
...Show More Authors

Increased attention to corporate governance with the increasing need for investors and other parties in the Iraqi market for securities of the information credible and confidence and greater transparency in the disclosure as well as the systems of governance lead to raise the value of the company and that by reducing the cost of capital and reduce the cost of financing, as well as that there are indications modern measurement can be adopted by the Iraqi market for securities for the purpose of evaluating the performance of listed companies and then raise their value.

   The research problem is that there is no framework or structure of the legal and local rules for the application of corporate governance in Iraq obliges

... Show More
View Publication Preview PDF
Publication Date
Tue Nov 09 2021
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The role of integration between the earned value management model and the value flow map in rationalizing the costs of construction projects: applied research in Al-Rasheed General Company for Construction Contracting
...Show More Authors

The research problem is that most of the construction projects exceed the planned value, due to the failure to implement the plans on time. The current study aims to monitor the implementation of the project and for each of the executed tasks of the table of quantities in order to detect deviations at the time they occur, evaluate the time and cost performance, and then identify the areas of waste and analyze the implementation of each task in order to diagnose the underlying problems and find possible and applicable solutions in the environment Iraqi. The research was applied in one of the companies specialized in the field of construction projects, and one of the most important conclusions reached is the possibility of applying

... Show More
View Publication Preview PDF
Publication Date
Sun Apr 03 2016
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Comparison of Asthma Control Test (ACT) with (GINA) guidelines in the Assessment of Asthma Control and determine if can use Asthmda Control Test ACT as alternative to Gina guidelines in control asthma.
...Show More Authors

Background: The gold standard in assessing asthma control is the Global Initiative for Asthma (GINA) criteria. And because of the difficulties of access to pulmonary functions tests, The ACT has the added  advantage that it does not require lung function assessment.
Objectives: The aim of this study is to assess asthma control through ACT score and GINA guideline, and to determine if the ACT can be as useful as the GINA-guidelines criteria in assessing asthma control in Iraq. Patient and method: Cross sectional study with comparing ACT vs. GINA guideline in control of asthma level. This study was conducted at Respiratory consultation unit of the Iraqi National center of early detection   of Cancer, Baghdad-Ira

... Show More
View Publication Preview PDF
Crossref
Publication Date
Mon Dec 28 2020
Journal Name
Journal Of The College Of Education For Women
The Effectiveness of Instructional Scaffolding Strategy in the Development of Academic Achievement and Critical Thinking in Female Second Year Secondary Students in Mathematics: محمد بن صنت الحربي , آمنة بنت سعيد بن جبل
...Show More Authors

This study aims to find out the effectiveness of instructional scaffolding strategy in the development of academic achievement and critical thinking of female second grade secondary mathematics students. Semi-experimental and relational descriptive method was used. The sample of the study consisted of (50) students divided into an experimental group and a control group. The experimental group was taught using scaffolding strategy whereas the control group was taught using traditional method. Pre- and Post-tests were used to achieve the objective of the study. The results of the study revealed that there are statistically significant differences in the mean scores of the experimental and control groups in the posttest for both the academi

... Show More
View Publication Preview PDF
Crossref
Publication Date
Sat Mar 01 2014
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Effectiveness of the organization and its role in achieving the requirements of Strategic success: A survey study of the opinions of a sample of workers at the Asia Telecom Company in Baghdad
...Show More Authors

The research aims present to highlight the importance of creating construction Organizational appropriate to achieve strategic success and reduce many of the negative effects experienced by organizations has been developing his questionnaire especially so was distributed to a sample of workers in the Asia-cellular as sample included (60) responsive 0 and can embody intellectual dilemma following questions (What are the dimensions of the organizational infrastructure, and what are the justifications for carrying out the reform and development cleared the organizational structure to make it more flexible) to contribute to the achievement of the strategic requirements for success of the organization surveyed.
Find recommended a number o

... Show More
View Publication Preview PDF
Publication Date
Sun Dec 20 2020
Journal Name
International Journal Of Research In Social Sciences And Humanities
THE EFFECT OF MAXIMUM PHYSICAL EXERTION EXERCISES ACCORDING TO THE ANAEROBIC THRESHOLD ON THE DEVELOPMENT OF EXPLOSIVE ABILITY AND THE SKILL OF SHOOTING BY JUMPING HIGH IN FRONT OF HANDBALL FOR YOUTH
...Show More Authors

The sports field is one of the fields that are concerned with the various methods and methods because of their positive impact on the development of actual training, the investment of the exerted effort in time, and through the follow-up of the researcher in the field and academic field, I noticed that there is a weakness in explosive ability, which affects performance and skill level during training and competition Therefore, the researcher decided to prepare maximum physical exertion exercises according to the anaerobic threshold as a principle of development in many physical and skill variables because good physical performance leads to reaching the best achievements and since the skill of shooting by jumping high - either constitutes a

... Show More
View Publication
Crossref