Purpose: Despite the high clinical accuracy of dynamic navigation, inherent sources of error exist. The purpose of this study was to improve the accuracy of dynamic navigated surgical procedures in the edentulous maxilla by identifying the optimal configuration of intra-oral points that results in the lowest possible registration error for direct clinical implementation. Materials and methods: Six different 4-area configurations were tested by 3 operators against positive and negative controls (8-areas and 3-areas, respectively) using a skull model. The two dynamic navigation systems (X-Guide® and NaviDent®) and the two registration methods (bone surface tracing and fiducial markers) produced four registration groups. The accuracy of the

Orthogonal Frequency Division Multiplexing (OFDM) is one of recent years multicarrier modulation used in order to combat the Inter Symbol Interference (ISI) introduced by frequency selective mobile radio channel. The circular extension of the data symbol, commonly referred to as cyclic prefix is one of the key elements in an OFDM transmission scheme. This paper study The influence of the cyclic prefix duration on the BER performance of an OFDM-VCPL (Orthogonal frequency division multiplexing - Variable Cyclic Prefix Length) system and the conventional OFDM system with frame 64-QAM modulation is evaluated by means of computer simulation in a multipath fading channel. The adaptation of CP is done with respect to the delay spread estimation

مفهوم معامل الارتباط كمقياس يربط بين متغيرين هذا يجلب انتباهنا إلى موضوع الإحصاء في كل المستويات. أكثر من ذلك هناك ثلاث نقاط خاصة هي اعتيادياً نشدد عليها كما يأتي:-

(1 معامل الارتباط هو الدليل المعياري والذي قيمته لا تعتمد على قياسات  

    المتغيرات الأصلية.

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Abstract

      In this study, we compare between the autoregressive approximations (Yule-Walker equations, Least Squares , Least Squares ( forward- backword ) and Burg’s (Geometric and Harmonic ) methods, to determine the optimal approximation to the time series generated from the first - order moving Average non-invertible process, and fractionally - integrated noise process, with several values for d (d=0.15,0.25,0.35,0.45) for different sample sizes (small,median,large)for two processes . We depend on figure of merit function which proposed by author Shibata in 1980, to determine the theoretical optimal order according to min

We need to know the basic facts concerning planning top and bottom limits including any critical levels or the threshold over which the cost would be much higher for land development. Therefore this paper concerned with Baghdad Municipality decision No.2/1004 dated 7/12/2004. The reason behind this decision is the hope to face up at least in the severe housing crisis in the city of Baghdad. This paper attempts to know the attitude of the local community in the general through a field study of people living near such dwelling where third floors are added of. This might indicate any positive or negative effects whether on short or long-term including its effect on the theoretical side including the population growth of Baghdad, the

Establishing sustainable cities and residential neighborhoods requires the development of new planning strategies, as adopting sustainable planning strategies when planning urban land uses for residential neighborhoods is necessary due to the large number of urban land use problems that have emerged during urbanization. The most prominent modern concept concerned with the land was the concept of sustainability, as sustainable planning aspires to link knowledge with sustainability through measures to achieve it. Therefore, sustainable planning works to apply the principles of sustainability in planning.

And in view of the circumstances that our country went through, which negatively affected various sectors and aspects of life, in

Most studies indicated that the values ​​of atmospheric variables have changed from their general rates due to pollution or global warming etc. Hence, the research indicates the changes of direct solar radiation values ​​over a whole century i.e. from 1900 to 2000 depending on registered data for four cities, namely (Mosul - Baghdad - Rutba - Basra. Moreover, attemptsto correlate the direct solar radiation with the temperature values have been ​​recorded over that period. The results showed that there is a decreasing pattern of radiation quantities over time throughout the study period, where the value of direct radiation over the city of Baghdad 5550 w/m² was recorded in the year 1900, but this ratio decreased cle

A theoretical analysis studied was performed to study the opacity broadening of spectral lines emitted from aluminum plasma produced by Nd-YLF laser. The plasma density was in the range 1028-1026 )) m-3 with length of plasma about ?300) m) , the opacity was studied as function of plasma density & principle quantum number. The results show that the opacity broadening increases as plasma density increases & decreases with the spacing between energy levels of emission spectral line.

The objective of this research to analyze the effectiveness of monetary policy in achieving economic stability and growth for the period 2004-2011 ،This period of time saw a fundamental shift in monetary policy after the issuing new law the Central Bank of the full independence of the monetary authority ،This is Prompt the monetary authority to bring about a change in the philosophy and objectives and the tools used to achieve the desired  goals ،Which give them the ability to control the size of the money supply and to achieve price stability Indeed، Monetary policy has been able to achieve the golden triangle of economic stability ،Consisted of staff، exchange rate stability and low and stable general level of prices