Acceptable Bit Error rate can be maintained by adapting some of the design parameters such as modulation, symbol rate, constellation size, and transmit power according to the channel state.

An estimate of HF propagation effects can be used to design an adaptive data transmission system over HF link. The proposed system combines the well known Automatic Link Establishment (ALE) together with variable rate transmission system. The standard ALE is modified to suite the required goal of selecting the best carrier frequency (channel) for a given transmission. This is based on measuring SINAD (Signal plus Noise plus Distortion to Noise plus Distortion), RSL (Received Signal Level), multipath phase distortion and BER (Bit Error Rate) fo

The design and implementation of an active router architecture that enables flexible network programmability based on so-called "user components" will be presents. This active router is designed to provide maximum flexibility for the development of future network functionality and services. The designed router concentrated mainly on the use of Windows Operating System, enhancing the Active Network Encapsulating Protocol (ANEP). Enhancing ANEP gains a service composition scheme which enables flexible programmability through integration of user components into the router's data path. Also an extended program that creates and then injects data packets into the network stack of the testing machine will be proposed, we will call this program

Steganography is a mean of hiding information within a more obvious form of
communication. It exploits the use of host data to hide a piece of information in such a way
that it is imperceptible to human observer. The major goals of effective Steganography are
High Embedding Capacity, Imperceptibility and Robustness. This paper introduces a scheme
for hiding secret images that could be as much as 25% of the host image data. The proposed
algorithm uses orthogonal discrete cosine transform for host image. A scaling factor (a) in
frequency domain controls the quality of the stego images. Experimented results of secret
image recovery after applying JPEG coding to the stego-images are included.

مشكلة البحث

              وتعد مرحلة المراهقة من اصعب المراحل التي يمر بها الفرد واخطرها اذ يطلق عليها بمرحلة التفكير المجرد ، وهي مرحلة حاسمة في حياته اذ تتكون لديه معالم الشخصية .أنهم خزين الامة الحقيقي من الطاقات الحيوية التي لا تنضب لذا يجب الاهتمام بهذه الشريحة من المجتمع وتطويرهم وتوجيههم لاسلم الطرق للحفاظ على مستقبلهم ومستقبل الا

With the growing use of electronic commerce has worked many companies, especially public shareholding to take advantage of them treated in the trade, so that the e-commerce part of the corporate environment, and this has made a career of accounting and auditing facing new challenges to the sophistication of the information and the rapid growth in the market for electronic commerce. And raised many questions about the ability of the audit profession to facing these challenges and how to audit operations of e-commerce and how to give confidence on websites, this sense it has become necessary keep the internal control systems of this technology and what has caused changes to the accounting system, and evolve to fit the developments that hav

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        The searchers opinions are variant in determining the extent of impacting political risk in the host country on foreign direct investment decision. (Aharoni,1966) found, in his questionary study for group of foreign companies operating in India, that a political stability is one of the two most important factors, besides the market size, in the attraction of foreign investment, and its availability means that whether this  specific country  is good for foreign investment. On the other side, (Green and Benntt, 1972) are present a variant opinion to Aharonis opinion. They are reach to result state that a political instability do not impact on the general distribution of foreign i

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The Arab economy suffers from many structural imbalances problems which are getting complicated by the appearance of the world economic variables.

This change held risky challenges for the Arab economies in the light of unsuitable regional and international conditions. Since that it has been very essential  for the Arab experts, especially those related to economy and politics, to face those new challenges or, at least, adapt with them believing that they can have both positive and negative impacts on the Arab economy.

This study has acquired its importance in the light of the critical levels the Arab economy reached out of the world economic variables, resulting in long-term

Abstract                                           

           The developments of technology and information that is sweeping the world based on the factors of pressure on the accounting profession in general, and the authors of the accounting information. That becouse the makers of administrative decisions have become in need of new information fit and the environmental situation of the new competition and try to enter new markets,