The huge evolving in the information technologies, especially in the few last decades, has produced an increase in the volume of data on the World Wide Web, which is still growing significantly. Retrieving the relevant information on the Internet or any data source with a query created by a few words has become a big challenge. To override this, query expansion (QE) has an important function in improving the information retrieval (IR), where the original query of user is recreated to a new query by appending new related terms with the same importance. One of the problems of query expansion is the choosing of suitable terms. This problem leads to another challenge of how to retrieve the important documents with high precision, high recall

Background: With the increasing demands for adult orthodontics, a growing need arises to bond attachments to porcelain surfaces. Optimal adhesion to porcelain surface should allow orthodontic treatment without bond failure but not jeopardize porcelain integrity after debonding.The present study was carried out to compare the shear bond strength of metal bracket bonded to porcelain surface prepared by two mechanical treatments and by using different etching systems (Hydrofluoric acid 9% and acidulated phosphate fluoride 1.23%). Materials and Methods: The samples were comprised of 60 models (28mm *15mm*28mm) of metal fused to porcelain (feldspathic porcelain). They were divided as the following: group I (control): the porcelain surface left u

The effect of thickness variation on some physical properties of hematite α-Fe2O3 thin films was investigated. An Fe2O3 bulk in the form of pellet was prepared by cold pressing of Fe2O3 powder with subsequent sintering at 800 . Thin films with various thicknesses were obtained on glass substrates by pulsed laser deposition technique. The films properties were characterized by XRD, and FT-IR. The deposited iron oxide thin films showed a single hematite phase with polycrystalline rhombohedral crystal structure .The thickness of films were estimated by using spectrometer to be (185-232) nm. Using Debye Scherrerś formula, the average grain size for the samples was found to be (18-32) nm. Atomic force microscopy indicated that the films had

Emails have proliferated in our ever-increasing communication, collaboration and
information sharing. Unfortunately, one of the main abuses lacking complete benefits of
this service is email spam (or shortly spam). Spam can easily bewilder system because
of its availability and duplication, deceiving solicitations to obtain private information.
The research community has shown an increasing interest to set up, adapt, maintain and
tune several spam filtering techniques for dealing with emails and identifying spam and
exclude it automatically without the interference of the email user. The contribution of
this paper is twofold. Firstly, to present how spam filtering methodology can be
constructed based on the concep

     The messages are ancient method to exchange information between peoples. It had many ways to send it with some security.

    Encryption and steganography was oldest ways to message security, but there are still many problems in key generation, key distribution, suitable cover image and others. In this paper we present proposed algorithm to exchange security message without any encryption, or image as cover to hidden. Our proposed algorithm depends on two copies of the same collection images set (CIS), one in sender side and other in receiver side which always exchange message between them.

      To send any message text the sender converts message to ASCII c

Teen-Computer Interaction (TeenCI) stands in an infant phase and emerging in positive path. Compared to Human-Computer Interaction (generally dedicated to adult) and Child-Computer Interaction, TeenCI gets less interest in terms of research efforts and publications. This has revealed extensive prospects for researchers to explore and contribute in the region of computer design and evaluation for teen, in specific. As a subclass of HCI and a complementary for CCI, TeenCI that tolerates teen group, should be taken significant concern in the sense of its context, nature, development, characteristics and architecture. This paper tends to discover teen’s emotion contribution as the first attempt towards building a conceptual model for TeenC

The reaction oisolated and characterized by elemental analysis (C,H,N) , 1H-NMR, mass spectra and Fourier transform (Ft-IR). The reaction of the (L-AZD) with: [VO(II), Cr(III), Mn(II), Co(II), Ni(II), Cu(II), Zn(II), Cd(II) and Hg(II)], has been investigated and was isolated as tri nuclear cluster and characterized by: Ft-IR, U. v- Visible, electrical conductivity, magnetic susceptibilities at 25 Co, atomic absorption and molar ratio. Spectroscopic evidence showed that the binding of metal ions were through azide and carbonyl moieties resulting in a six- coordinating metal ions in [Cr (III), Mn (II), Co (II) and Ni (II)]. The Vo (II), Cu (II), Zn (II), Cd (II) and Hg (II) were coordinated through azide group only forming square pyramidal

 ٳن العلاقة بين التخطيط والتنمية، تكتسب᾽ شكلها وطبيعتها من خلال دور التخطيط في ٳخضاع عملية التغيير والتحوّل للأوضاع الاقتصادية من وضع الى وضع آخر أكثر تقدما̋ عن طريق ٳعتماد منهج التخطيط لتحديد معالم خطوط السير المجدول زمنيا̋ لعملية التغيير والتحوّل وفقا̋ لرؤية الحكومة وفلسفتها باتجاه الانتقال من وضع ٳقتصادي وٳجتماعي متخلف الى وضع ٳقتصادي وٳجتماعي آخر يسمح بجعل عملية النمو مستمرة، ويمكن تبيّن تلك

This paper interest to estimation the unknown parameters for generalized Rayleigh distribution model based on censored samples of singly type one . In this paper the probability density function for generalized Rayleigh is defined with its properties . The maximum likelihood estimator method is used to derive the point estimation for all unknown parameters based on iterative method , as Newton – Raphson method , then derive confidence interval estimation which based on Fisher information matrix . Finally , testing whether the current model ( GRD ) fits to a set of real data , then compute the survival function and hazard function for this real data.