143 research outputs found

    Radio frequency radiation measurement for base tower station safety compliances: a case study in Pulau Pinang Malaysia

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    The residence of Pulau Pinang and Malaysia generally are worried with the possible health effects due to Base Tower Station (BTS) radiation. Particularly, the residents of Pulau Pinang are utilizing their mobile phones for multiple kind of tasks including communications, browsing the internet and other applications. With the recent advances in mobile communication technologies, the end user demanded a better coverage, great communication services, and faster speed for internet browsing. To fulfill the demand, service provider and communication companies are providing plenty of communication base tower leading to the beliefs of that the tower emitted radiation and cause harmful effect to human health and voiced out and complain to the municipal councils in Malaysia. In this paper, a measurement was conducted to study electromagnetic fields (EMF) radiation level in Pulau Pinang. The measurement is compared with the international standard provided by International Commission of Non-Ionizing Radiation Protection (ICNIRP). Far field measurement of different values of long term evolution (LTE) exposure was demonstrated in radiofrequency (RF) shielded environment. LTE850, LTE1800 and LTE2600 field exposure was compared in term of itsโ€™ electrical field and power density that adhere to the standard provided by ICNIRP

    An Accurate Performance Analysis of Hybrid Efficient and Reliable MAC Protocol in VANET under Non-saturated Conditions

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    Vehicular Ad Hoc Networks (VANETs) is a technology supporting two types of applications, safety and service applications with higher and lower priorities respectively. Thereby, Medium Access Control (MAC) protocol is designed to provide reliable and efficient data broadcasting based on prioritization. Different from the IEEE 1609.4 (legacy), HER-MAC protocol is a new multi-channel MAC proposed for VANETs, offering remarkable performance with regards to safety applications transmission. This paper focuses on the analysis of packet delivery ratio of the HER-MAC protocol under non-saturated conditions. 1-D and 2-D Markov chains have been developed for safety and non-safety applications respectively, to evaluate mathematically the performance of HER-MAC protocol. The presented work has taken into account the freezing of the backoff timer for both applications and the backoff stages along with short retry limit for non-safety applications in order to meet the IEEE 802.11p specifications. It highlights that taking these elements into consideration are important in modeling the system, to provide an accurate estimation of the channel access, and guarantees that no packet is served indefinitely. More precise results of the system packet delivery ratio have been yield. The probability of successful transmission and collisions were derived and used to compute the packet delivery ratio. The simulation results validate the analytical results of our models and indicate that the performance of our models outperformed the existing models in terms of the packet delivery ratio under different number of vehicles and contention window

    Reduction of cavity length dependence and improvement of characteristics of 1.55 ยตm quantum dot based LASER using Indium Nitride

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    This paper presents the improvement of certain important characteristics of 1.55 ยตm laser by reducing the dependence of cavity length using InN based quantum dot in the active layer of the device structure. The improvement of these characteristics has been investigated in terms of ultra low threshold current density, minimization of internal loss, enhancement of the modal gain, external differential efficiency and the photon lifetime. In this paper these characteristics have been investigated using InN based quantum dot in the active layer of the laser structure and compared with GaN and AlN based quantum dot laser. The comparison results reveal that InN based quantum dot provides lower threshold current density, reduced internal loss compared to GaN and AlN quantum dot based laser. Beside these enhanced modal gain, improved efficiency and higher photon lifetime have also been reported using InN based quantum dot in the active layer of the laser structure. In addition to these improvements obtained from the numerical results it is ascertained that InN based quantum dot in the active layer of the laser structure offers weaker dependence of cavity length on these characteristics. From the results it is revealed that InN can be a promising material to design high performance quantum dot based laser operating at 1.55 ยตm with reduced cavity length dependence in the very near future

    Molecular identification and genetic diversity study of the Iraqi truffles

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    The aim of this study is to investigate the molecular identification of the Iraqi truffles species and a better understanding of genetic diversity in the center of the truffles habitat. Thirty-two samples were collected from the Iraqi desert and local markets. Samples were chosen depending on the morphological diversity of the fruit body and sample collection area. Results of ITS region sequencing for the 32 samples showed two genuses Tirmania and Terfezia are the main dominant, 4 species of Tirmania pinoyi and 28 species of Terfezia claveryi. All species sequences were deposited in NCBI GenBank and all had accessions number. The neighbor-Joining method was used to generate a phylogenic tree to study the genetic diversity of the ITS sequences for the 32 Iraqi truffle samples. Results showed a high genetic diversity for the Iraqi truffles samples. The phylogenic study showed Iraqi truffles clustered with different groups as a clade with the reference sequences from other countries represent three continents Asia, Africa, and Europe. Also, we found in this study a unique cluster group for the Iraqi sequences for T. pinoyi and T. claveryi truffles cluster in one group and do not match with any reference sequences used in this study. This is a piece of strong evidence proofed the Iraqi habitat could be the origin of center diversity for the T. pinoyi and T. claveryi truffles

    LoRaWAN-based hybrid internet of wearable things system implementation for smart healthcare

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    This study introduces the design and development of an Internet of Wearable Things-based Hybrid Healthcare Monitoring System (IoWT-HHMS) for smart medical applications. The system incorporates smart wearable sensing units for real-time, remote monitoring of vital health parameters such as Blood Pressure (BP), Heart Rate (HR), and Body Temperature (BT). A key innovation is the development of a hybrid wireless network communication mechanism within the IoWT-HHMS, utilising the FiPy microcontroller. This mechanism supports both short- and long-range connectivity and integrates an algorithm for efficient data acquisition and updating to the IoT platform. The IoWT-HHMS has undergone extensive testing and validation across various scenarios, including sensor functionality, performance of Wi-Fi and LoRaWAN networks, hybrid network connectivity, and accuracy assessment using the Datacake dashboard. The tests evaluated crucial aspects such as communication reliability, power consumption, and latency. The results demonstrate the system's high stability and accuracy in reading health parameters. Comparisons with reference devices reveal impressive accuracy levels for Systolic BP (SBP), Diastolic BP (DBP), HR, and BT, recording 96.37 %, 95.17 %, 97 %, and 98.57 % accuracy, respectively. Both Wi-Fi and LoRaWAN networks proved reliable in indoor and outdoor settings, maintaining data transmission over distances up to 1.5 km without data loss. In conclusion, the developed IoWT-HHMS shows great promise for efficient and effective real-time remote monitoring of patients' health conditions using an innovative hybrid wireless network communication mechanism

    A Survey on LoRaWAN Technology: Recent Trends, Opportunities, Simulation Tools and Future Directions

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    Low-power wide-area network (LPWAN) technologies play a pivotal role in IoT applications, owing to their capability to meet the key IoT requirements (e.g., long range, low cost, small data volumes, massive device number, and low energy consumption). Between all obtainable LPWAN technologies, long-range wide-area network (LoRaWAN) technology has attracted much interest from both industry and academia due to networking autonomous architecture and an open standard specification. This paper presents a comparative review of five selected driving LPWAN technologies, including NB-IoT, SigFox, Telensa, Ingenu (RPMA), and LoRa/LoRaWAN. The comparison shows that LoRa/LoRaWAN and SigFox surpass other technologies in terms of device lifetime, network capacity, adaptive data rate, and cost. In contrast, NB-IoT technology excels in latency and quality of service. Furthermore, we present a technical overview of LoRa/LoRaWAN technology by considering its main features, opportunities, and open issues. We also compare the most important simulation tools for investigating and analyzing LoRa/LoRaWAN network performance that has been developed recently. Then, we introduce a comparative evaluation of LoRa simulators to highlight their features. Furthermore, we classify the recent efforts to improve LoRa/LoRaWAN performance in terms of energy consumption, pure data extraction rate, network scalability, network coverage, quality of service, and security. Finally, although we focus more on LoRa/LoRaWAN issues and solutions, we introduce guidance and directions for future research on LPWAN technologies

    Measurement of normal optic nerve for Sudanese pediatric using magnetic resonance imaging

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    Background: Much congenital and intracranial pathology may affect optic nerve (ON) and caused increased or decreased in size, so the measurement is crucial and aiding in diagnosed of some neurogenic and endocrine disorders. The aim of this study was to measure the normal ON length and diameter by magnetic resonance imaging among pediatric at Khartoum state Sudan.Methods: This was descriptive, cross section study,ย  done in 100 Sudanese pediatrics with age from 1 month to 15 years came to Magnetic resonance imaging (MRI) department for MRI brain at three hospitals in Khartoum stateย  (Al-Amal national hospital, Al-Zaitona hospital and Modern Medical Center) during the period from December 2019 to March 2020, all of patients had no pathological or medical condition that may affect the orbits and optic nerve (OON), any child with and medical condition or pathology related to orbits excluded from study sampling. The data were collected by data collection sheet designed especially for this study then analyzed.Results: The study found that the mean diameter of ON was 2.06ยฑ0.44 mm, the mean length of right ON was 31.54ยฑ4.11 mm, there is no significant different in measurement between males and females (p>0.05), there was strong significant correlation between ON length and diameter with children age (r=0.592**, 0.654**, p<0.001 respectively).Conclusions: The study concluded that there was strong correlation between right and left ON diameter and length with age

    Assessment of worn textile antennasโ€™ exposure on the physiological parameters and well-being of adults

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    This paper presents the assessment of short-term wireless body area network (WBAN) exposure, which is operated at the industrial, scientific, and medical (ISM) band (2.45 GHz) in the vicinity of the human body. The experiment utilizes two popular textile antenna topologies, a planar monopole and a patch antenna as the radiating sources. The objective of this experiment is to investigate whether the exposure from WBAN may influence the physiological parameters (body temperature, blood pressure, and heart rate) and the well-being of the wearer. Counter-balanced, crossover, and the single-blind method was applied in the experimental setup. P-value is the probability value, under the assumption of no effect or no difference (the null hypothesis) of obtaining a result equal to or more extreme than what was actually observed. If P&lt;; 0.05, it indicates that P-value will be less than the level of significance. Thus, the null hypothesis (no effect or no difference) can be rejected, and it can be concluded that there exist effects to the respondents. The results showed that there is statistically no significant difference between the active exposure and the Sham (no exposure) which may affect the physiological parameters and well-being of the wearers, with P&gt;0.05, which failed to reject the null hypothesis (no effect)
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