Radiation measuring devices need to process calibration which
lose their sensitivity and the extent of the response and the amount of
stability under a changing conditions from time to time and this
period depends on the nature and use of field in which used devices.
A comparison study was done to a (451P) (ionization chamber
survey meter) and this showed the variation of calibration factor in
five different years. This study also displayed the concept of
radiation instrument calibration and necessity of every year
calibration of them.
In this project we used the five years calibration data for ionization
chamber survey meter model Inspector (451P) to get that the values
of Calibration Factor (CF) and Response (1/CF). The value deviation
(Δ%) of CFs for four years of calibration in comparison of CF for the
year 2007 are very high and the device under research is not good to
use in field and reliable because the ionization chamber is very
sensitive to humidity and must calibrate a year or less, or during
every two years and must maintain carefully to reduce the discarded
effects to the measurements.
Vehicular ad hoc network (VANET) is a distinctive form of Mobile Ad hoc Network (MANET) that has attracted increasing research attention recently. The purpose of this study is to comprehensively investigate the elements constituting a VANET system and to address several challenges that have to be overcome to enable a reliable wireless communications within a vehicular environment. Furthermore, the study undertakes a survey of the taxonomy of existing VANET routing protocols, with particular emphasis on the strengths and limitations of these protocols in order to help solve VANET routing issues. Moreover, as mobile users demand constant network access regardless of their location, this study seeks to evaluate various mobility models for vehi
... Show MoreThe agent-based modeling is currently utilized extensively to analyze complex systems. It supported such growth, because it was able to convey distinct levels of interaction in a complex detailed environment. Meanwhile, agent-based models incline to be progressively complex. Thus, powerful modeling and simulation techniques are needed to address this rise in complexity. In recent years, a number of platforms for developing agent-based models have been developed. Actually, in most of the agents, often discrete representation of the environment, and one level of interaction are presented, where two or three are regarded hardly in various agent-based models. The key issue is that modellers work in these areas is not assisted by simulation plat
... Show MoreThe bandwidth requirements of telecommunication network users increased rapidly during the last decades. Optical access technologies must provide the bandwidth demand for each user. The passive optical access networks (PONs) support a maximum data rate of 100 Gbps by using the Orthogonal Frequency Division Multiplexing (OFDM) technique in the optical access network. In this paper, the optical broadband access networks with many techniques from Time Division Multiplexing Passive Optical Networks (TDM PON) to Orthogonal Frequency Division Multiplex Passive Optical Networks (OFDM PON) are presented. The architectures, advantages, disadvantages, and main parameters of these optical access networks are discussed and reported which have many ad
... Show MoreThe survey and checklist of invasive species of the insects in some different localities of Iraq are revised; 24 invasive species were documented until December 2018 during the current investigations. The species distributions, common names and synonyms are given.
The current investigation included all of exotic species in Iraq, which are not collected during this study.
Nowadays, huge digital images are used and transferred via the Internet. It has been the primary source of information in several domains in recent years. Blur image is one of the most common difficult challenges in image processing, which is caused via object movement or a camera shake. De-blurring is the main process to restore the sharp original image, so many techniques have been proposed, and a large number of research papers have been published to remove blurring from the image. This paper presented a review for the recent papers related to de-blurring published in the recent years (2017-2020). This paper focused on discussing various strategies related to enhancing the software's for image de-blur.&n
... Show MoreTwelve species of philodromid crab or running crab spiders (Philodromidae) have been recorded in Armenia. Nine species are new to the spider fauna of this country: Philodromus cespitum (Walckenaer, 1802); Philodromus emarginatus (Schrank, 1803), Philodromus rufus Walckenaer, 1826; Rhysodromus histrio (Latreille, 1819), Thanatus atratus Simon, 1875; Thanatus formicinus (Clerck, 1757); Thanatus imbecillus L. Koch, 1878; Thanatus vulgaris Simon, 1870 and Thanatus pictus L. Koch, 1881.