This work presents the use of laser diode in the fiber distributed data interface FDDI networks. FDDI uses optical fiber as a transmission media. This solves the problems resulted from the EMI, and noise. In addition it increases the security of transmission. A network with a ring topology consists of three computers was designed and implemented. The timed token protocol was used to achieve and control the process of communication over the ring. Nonreturn to zero inversion (NRZI) modulation was carried out as a part of the physical (PHY) sublayer. The optical system consists of a laser diode with wavelength of 820 nm and 2.5 mW maximum output power as a source, optical fiber as a channel, and positive intrinsic negative (PIN) photodiode with maximum responsivity at wavelength of 820 nm as a detector. Practical tests were carried out on the laser diode showed that the output characteristics and spectral characteristics of the laser diode depend largely on the drive current. The maximum separation distance between successive stations in the ring was 5.4 km. From the performance tests, it was concluded that the maximum throughput and maximum access delay are directly proportional to length of the transmitted information. A trade off between the transmitted information length and the maximum access delay is needed.
This study seeks to address the impact of marketing knowledge dimensions (product, price, promotion, distribution) on the organizational performance in relation to a number of variables which are (efficiency, effectiveness, market share, customer satisfaction), and seeks to reveal the role of marketing knowledge in organizational performance.
In order to achieve the objective of the study the researcher has adopted a hypothetical model that reflects the logical relationships between the variables of the study. In order to reveal the nature of these relationships, several hypotheses have been presented as tentative solutions and this study seeks to verify the validity of these hypotheses.
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In our research, we introduced new concepts, namely *and **-light mappings, after we knew *and **-totally disconnected mappings through the use of -open sets.
Many examples, facts, relationships and results have been given to support our work.
Studied red beetle life on each of the yen and wheat durum wheat, barley, corn, rice, chickpeas, ground peanuts and beans in Living situation constant temperature and relative humidity of 65% for a period of 66 days was the life cycle of the insect different from one substance to another ....
كان لنهاية الحرب الباردة وعولمة العالم على وفق رؤية كونية تتجاوز حدود ومفاهيم السيادة الوطنية والقومية الاثر الواضح في ترتيب العلاقات الدولية , واصبحت تلك العلاقات تدور حول محورين الاول .. هو الاعتماد المتبادل بين الدول من اجل الوصول الى خطوط مشتركة للمصالح المختلفة بين هذه الدول . والآخر.. هو تبعية الدول الضعيفة للدول القوية لافتقار الاولى توفير الحاجيات الى مواطنيها . هذا يشير الى نشأة علا
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In this work, the notion is defined by using and some properties of this set are studied also, and Ù€ set are two concepts that are defined by using ; many examples have been cited to indicate that the reverse of the propositions and remarks is not achieved. In addition, new application example of nano was studied.
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The research starts from a fundamental problem about how top management team can realize the uncertainty. Strategic conversation has been introduced as a way for top management team to deal with uncertainties. Within the current research model, the strategic conversation was considered as an independent variable and uncertainty as dependent variable. The researcher used the survey method by distributed a questionnaire in the Administration and Economics College, University of Baghdad. Samples are 40 faculty participant of scientific committee members were distributed in seven scientific departments. The data were statistically analyzed by mean and the standard deviation. The hypotheses were tested through the use of correlation and regressi
... Show MoreMaking the data secure is more and more concerned in the communication era. This research is an attempt to make a more secured information message by using both encryption and steganography. The encryption phase is done with dynamic DNA complementary rules while DNA addition rules are done with secret key where both are based on the canny edge detection point of the cover image. The hiding phase is done after dividing the cover image into 8 blocks, the blocks that are used for hiding selected in reverse order exception the edge points. The experiments result shows that the method is reliable with high value in PSNR
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Jurisprudence is one of the most honorable sciences in value, and the greatest of them in reward. Through it, the rulings of religion are known. He, may God’s prayers and peace be upon him, said: ((Whoever God desires good, He gives him understanding of religion)), and through it, the legal rulings and what is related to them are known from what is permissible and forbidden.
And prayer is the believer’s ascent to his Lord, with which the heart is at peace and the soul is at ease. If he, may God’s prayers and peace be upon him, was overwhelmed by an issue or something became difficult for him, he would panic in prayer and be reassured by it. It was necessary for the students of knowledge to investigate its aspects and its secrets