American Journal of Scientific Research

Issue 101
April, 2014

Shapes: A Self-Healing Model for an Agricultural Pervasive Sensor Networks
5-15
K. Vanitha and G. Radhamani

Abstract:
Pervasive Networks are self-regulating networks. These networks are being deployed and experimented for several agricultural applications enriched with autonomic functionalities. A Pervasive Network is said to be complete only when the sensors are attached. A Pervasive Environment is dynamic, self-configuring, self-regulating and self-healing. Thus, a wireless sensor network becomes a sound means to deploy and realize the pervasiveness. Every sensor network requires an initial placement method. The objective of the paper is to define a self-healing model of data aggregation for Agricultural Applications. The Placement of sensor nodes is based on a new topology named Gallery. The topology and the algorithm ensure the novel localization of sensor nodes. An algorithm SHAPES using theory of soft sets is devised for handling uncertainty. A technique, wait-n-relay is introduced for aggregating sensed data using mobility nodes. An experimental test bed is created using XBee-PRO RF modules, for sensing agriculture practices with static nodes and mobility nodes.
Keyword: Gallery Topology, Self-healing, Precision Agriculture, Pervasive Sensor Networks, Soft sets.

The Relationship Between Students' Attitudes Towards E-Learning and Self-Directed Learning Among A Sample of Students From the Faculty of Education at the University of Jordan in Light of Gender and Year Variables
16-31
Firas G. Tannous and Intesar G. Tannous

Abstract:
This study aimed to examine the relationship between students' attitudes towards e-learning and self-directed learning among a sample of students from the faculty of education at the University of Jordan in light of the variables of gender and the school year. To answer the questions of the study, it was selected a sample consisting of (147) students in the first and fourth school year, and two scales were used in the study: a scale for students' attitudes toward e-learning and self-directed learning. The results showed the existence of a statistically significant correlation at the level of significance (0.05 = a) between students' attitudes toward e-learning and self-directed learning on the total score and all sub-dimensions of the two scales. Moreover, the results showed a lack of statistically significant differences at the level of significance (0.05 = a ) in students' attitudes towards e-learning due to the variables of the school year , gender, and the interaction between them on the total score of the scale, while the results showed statistically significant differences on the dimensions of the following subsidiary of the scale ( ease of e-learning use, technological and pedagogical support, e-learning stressors ) according to the variables of gender and the school year. The results of the analysis of covariance (ANCOVA) showed statistically significant differences at the level of significance (0.05 = a) in students' attitudes toward self-directed learning on the total score of the scale attributed to the different level of school year, while the results did not show any statistically significant differences attributed to the variables of gender and the interaction of school year and gender. However, as for the dimensional sub- scale, there are statistically significant differences at the level of significance (0.05 = a) in students' attitudes towards learning strategies depending on the variable of the school year, while the results did not point to the existence of statistically significant differences of the other sub- scale dimensions.
Keywords: Attitudes, E-Learning, Self Directed Learning.


A New Class of Preconditioners for Large-Scale Linear Systems and Linear Programming from Interior Point Methods

32-40
Alireza Alizadedize

Abstract:
Prerequisites for a class of iterative solution of linear systems, there have been proposed methods of internal points. For donation methods, linear devices are symmetric and indefinite. The device can be reduced to a system of equations is normally recorded in the ledger. We show that the preconditions for normal equations, the equations are added to the device, while the reverse does not hold. This class is a pre-condition near the linear programming solution when conditions are too bad to better. Preconditioned system can be reduced to a positive definite. Techniques developed for a relatively complex because of competing implementations of previous columns is unknown. The preconditioned conjugate gradient method used, and the Cholesky decomposition on the big issues - the scale is such that the approach compares favorably to the Cholesky decomposition non-zero elements is quite high.
Keywords: Linear programming, interior-point method precondition construction, devices added.


A New Approach for Envelope of Lightweight Concrete Mix Design

41-50
Hoshyar Imani Kalehsar and Soheyl Fatemi

Abstract:
One way to reduce excess material would be to lighten the load on a structure with the use of affordable lightweight high performance concrete (ALWHPC). Most or all lightweight high performance concrete mixes used today include lightweight aggregates as the coarse aggregate and sand for the fine aggregate. ALWHPC mix designs contain all lightweight aggregates and cementitious materials. Instead of 115–120 pcf, ALWHPC mix designs range from 88–100 pcf and strengths from 2,700–8,700 psi compressive strength. Lightweight aggregate is the primary difference between normal-weight and lightweight concrete. Lower density aggregates are primarily used for insulating, temporary construction, or moderate-strength concrete applications. Higher density aggregates, such as expanded shales, clays, slates, slags, pumice, and scoria, which yield higher strength concrete, are used for structural lightweight concrete applications. This research will explore the use of local lightweight aggregates along with different local cementitious materials and admixtures to create an affordable lightweight high performance concrete mix design.
Keywords: Envelope, Lightweight Concrete, Mix Design, Cementitious Materials.


Development a Systematic Approach for Risk Modeling of Disaster in Transportation Systems

51-61
Mehdi Behniafard

Abstract:
Transportation networks are an important and critical backbone of modern society. Physical damage and functional loss to transportation infrastructure systems impair post-disaster response and recovery, leading to substantial socio-economic consequences. This research develops a systematic approach for risk modeling and disaster management of transportation systems based on earthquake engineering. First we use the performance metrics to explore efficient methodologies for maximization of the overall system functionality. Then, the regions potentially unreachable after a damaging earthquake are identified promptly by using network reachability algorithms that provide essential information for rapid emergency response decision-making. Finally, an integrated simulation model of travel demand is developed to approximate the “abnormal” post-earthquake travel patterns and evaluate the functional loss of the transportation systems.


Limites Du Désherbage Chimique En Bananeraies Industrielles De Dabou Au Sud De La Côte D’ivoire

62-72
Prosper Yao Kouadio, Marie-Solange Tiébré, Hervé Roland Kouassi, Justin N’Dja Kassi and Edouard Kouakou N’Guessan

Abstract:
L’étude des limites du désherbage chimique en bananeraies industrielles de Dabou intervient dans le contexte de la production de la banane durable en Côte d’Ivoire.Elle s’est fixé pour objectif d’identifier les faiblesses de l’utilisation de herbicides aussi bien au niveau de la flore, du coût de la production que sur la santé des travailleurs. Par conséquent, des études floristique, phytosociologique, technique et économique du désherbage chimique, associées à des tests d’efficacité des herbicides usuels ont été conduites dans 4 plantations industrielles à DABOU et auprès des firmes agropharmaceutiques. Elles ont révélé que ces plantations ont une flore très diversifiée dominées par quelques espèces abondantes qui bénéficient des effets conjugués des facteurs du milieu, des faiblesses des applications herbicides liées aux intempéries et aux coûts élevés du désherbage chimique. Aussi la lutte chimique contre les mauvaises herbes présente-elle de nombreux dangers pour les travailleurs des plantations.
Keywords: Adventice, banane, Côte d’Ivoire, herbicides, santé humaine.

The Effect of a Training Program on the Development of Educational Competencies for Teachers' of Physical Education for Joining Students with Disabilities in Ordinary Schools
73-83
Ibrahim Al Shihab


Quality of Service Provided in Isfahan Hotels from the Perspective of Foreign Tourists using the SERVQUAL Model

84-92
Fatemeh Abbasi, Ahmad Reza Shekarchi Zadeh Isfahani and Naser Khani

Abstract:
Purpose: The aim of this study was to investigate service quality as an important field in service marketing, In this study, the service quality in hotels of Isfahan city as one of the most attractive tourist destination in Iran – has been examined from the perspective of foreign tourists. The aim of selecting foreign tourists as respondents was to evaluate the possible role of cultural differences in the service quality perceptions. Method: Considering the descriptive nature of this study, a survey method was used for data collection. Accordingly, using a questionnaire as the survey tool, the respondents were simply selected randomly. Finally, as sample size, 36 foreign tourists from different countries participated in the study. Findings: The result of the analysis showed that perceptions and expectations of respondents were equal in all quality dimensions (i.e. tangibles, assurance, commitment, empathy, responsiveness, equipment, food, and security). Furthermore, there was a significant difference between participants’ perceptions in terms of gender. On the other hand, there was not any significant difference in terms of their age, marital status, education level, income level, occupation, and the country of origin. Collectively, it can be concluded that in the context of this study, cultural differences had no role in the perception of tourists regarding service quality in Isfahan hotels.
Keywords: Tourism, Isfahan Hotels, Service Quality, SERVQUAL model, perceptions, and expectations.


Security in Ad Hoc Networks

93-101
Hemen Peshnamaz, Hassan Rashidi and Amirabbas Mahdavi Shahri

Abstract:
Wireless ad hoc networks have been proposed to offer and support dynamic scenarios where no wired-network existed. Ad hoc environments introduce two main problems not commonly faced by traditional stable network routing protocols. These are the lack of constant infrastructure support and the frequent changes to network topology. At the physical level, wireless channels offer poor protection to protocol packets and are susceptible to signal interference, jamming, eavesdropping, and distortion. There are several methods to prevent attacks to ad-hoc networks, for instance encryption methods like implementing Public/Private key algorithms for communication among wireless nodes.
Keywords: Ad-hoc Network, Routing Protocols, Cryptography, Digital Certificate.

An Efficient Adaptation Model in Peer to Peer Networks to Improve Search Response Time
102-109
L. Rikhtechi, A. Patooghy and M. Fazeli

Abstract:
Search is an essential operation in almost all applications of peer to peer networks including file sharing, file systems, news services, etc. This paper proposes and evaluates an efficient search algorithm for peer to peer network which minimizes the search response time by efficiently utilization of network resources. This is done by the use of an adaptation model proposed to effectively match the overlay network into the underlying physical network in peer to peer networks. Evaluation of the proposed search algorithm along with the proposed adaptation model is done by several simulations in different working conditions i.e., different network sizes, several query scenarios. Results of simulations show that the proposed search algorithm significantly reduces the search response time that in peer to peer networks. In comparison with the previously proposed algorithms, the proposed search algorithm shortens the search response time by at least 33% which in turn enhances the overall performance of a peer to peer network by at least 23%.
Keywords: Peer to Peer networks, search algorithms, overlay network, physical network,performance.