IRAQI JOURNAL OF COMPUTERS, COMMUNICATIONS, CONTROL AND SYSTEMS ENGINEERING

In recent years Quadcopter has been used in many applications such as military, security & surveillance, service delivery, disaster rescue and much more due to its flexibility of flying. In this paper, Quadcopter will be used for mail delivery between many locations that is received from the end user. The Quadcopter will execute an autonomous flight using the concept of companion PC. Raspberry PI 3 (RPI3) will control the Quadcopter by command the controller of the drone (Pixhawk) by using DroneKit-Python API to send MAVLink messages to the Ardupilot. This concept is useful to perform an additional task to the autopilot and provide such a smart capability like image processing and path planning which cannot be done by the flight controller alone. Basically, the idea has been stimulated and the code has been tested by using the SITL Simulator with MAVProxy under Ubuntu environment. The result of controlling the Quadcopter using Python script was excellent and give a motivation to implement the same script on a real Quadcopter. The implementation on real Quadcopter was perfect as it has given the same behavior as the SITL drone in the simulation.

Lithium niobate (LiNbO3) nanostructure thin film was prepared and deposited on the substrates made of quartz by utilizing pulse laser deposition (PLD) technique. The effect of substrate temperature changing on the optical and structural properties of LiNbO3 films was investigated and studied. The chemical mixture was prepared by mixing the raw material (Li2CO3, Nb2O5) with Ethanol liquid without any further purification, at the stirrer time 3hrs without heating, then the formed material was overexposed to annealing process at 1000°C for 4hrs. LiNbO3 nanostructure thin film was characterized and analyzed by utilizing the Ultra-Violet visible (UV-vis) and X-Ray Diffraction (XRD). The UV-vis results showed that the increase in the substrate temperature to 300°C leads to decrease in the values of transmission (T%), absorption (A) and optical energy gap (Eg) and increase in the values of reflection (R%) and refractive index (n). While, the XRD results explained that the LiNbO3 structure became more pure and crystalline with increase the substrate temperature, because the intensity of the phase 2θ at the value of 34.8°, 40.06° and 48.48° correspond to (110), (113) and (024) planes disappeared at the substrate temperature 300°C. So, all presented results give a good indication to use LiNbO3 nanostructure thin film prepared at the substrate temperature 300°C for manufacturing the optical waveguide to give the best results.

The most necessary factors effect on the standard of broadband access services in mobile systems are WIMAX signal throughput and area coverage range. The environment controls are based on the sign power of any radio communication system. The sign power in any base station site relies on the space between the transmitter and the receiver, carrier frequency for the transmitter and the receiver along on the path loss. One of the most generally utilized experimental model to predict the path loss is the COST-231 Hata model. In this paper, the path loss rates have calculated based on the WIMAX criterion frequency at an area with 3.5GHz, that constant distances (7km) of transmitting base station into receive base station in urban, suburban environments. The execution of the COST-231 Hata paradigm and optimized paradigm are rated over the path loss. This model is optimized using Genetic Algorithm Technique using a computational tool MATLAB. Path loss results acquired show that the optimized paradigm rates a little higher than rates standard. The distance (7km)is good because of achieving the lowest value for path loss.

Recently, the world has been interested in transferring data between different devices. The transmission of data must be encrypted so that the intended receiver can only read and process a secret message. Hence, the security of information has become more important than earlier. This paper proposes the least significant bit Steganography method to hide a secret message inside an image cover via using dynamic stego-key. To check the effectiveness of the proposed method, many factors are used for evaluation and compared with another method. The results illustrate more robustness at steganography since stego-key depends on the cover image to hide a secret message.

The study and evaluation of digital communication systems in low signal-to-noise power ratio (LSNR) environments is a hot and important topic due to its wide contemporary applications. This review is an attempt to focus on the most distinctive vital parameters required in the analysis and design of such systems. It includes a brief literature survey for many algorithms, techniques, methodologies, and mitigations that have been used to overcome the high noise problem encountered in these systems in order to guarantee reliable communication. Amongst these topics, the study reviews the most widely utilized modulation techniques in LSNR communication systems such as the On-Off Keying (OOK) and binary PSK schemes. The capacity for both AWGN and wireless fading channels is also discussed along with a clarification of the minimum limits in these types of channels. On the other hand, some important and recommended detection and estimation techniques for low power communication systems are briefly covered. This unified study has additionally discussed spectral efficiency and bit energy trade- off within the low-power, and broadband systems, and different limitations are stated clearly. Finally, the survey throughout this paper recommends some significant techniques that can be used in the analysis and design of successful communication systems in LSNR regimes.

The MQTT protocol is one of the Internet of Things (loT) application protocols. It is based on publishing/subscribing messaging patterns. This protocol uses a broker to manage the communication between the subscribers and the publishers over the internet. There were two problems associated with the implementation of this protocol. The first one, there are many sensors generating huge data using the very simple IoT architecture. These big data may lead to congestion on the internet and thus will cause several disadvantages such as decreasing throughput, packet loss, and delay, which in turn may affect the performance of the MQTT broker, thus affecting the mechanism of the performance of the IoT application. The second problem, the MQTT protocol does not contain a priority management algorithm which is considered a very important and special issue in health applications. In this paper, a smart gateway is designed to enhance the MQTT networks. This work introduced the smart e-health gateway used in MQTT based remote Electrocardiogram (ECG) monitoring system. A new architecture has been implemented that contains two new components, the local broker and the publisher /subscriber (pub/sub) models. The local broker works in the local network and the publisher /subscriber (pub/sub) model is responsible for the process of smart in the gateway. One of the smart applications was used is a filter application. We've taken the data filtering side and give it a priority, as an example in order to know the possibility of achieving the architecture of the gateway that was created in our work. And is this architecture valid to work or invalid. Therefore, we conducted a test using the application of ECG signal filtration and give priority to patients according to the case of an urgent for each patient. The R-peaks were calculated from the ECG signals-peaks for the identification of heart rate. The urgent level will be classified depending on the beats rate feature. The proposed smart gateway function is to manage the data rate that will pass through to the internet. In the case of high urgent level, all the packets will be passed, while in case of a low level, the least possible data will be passed. The proposed system scenarios are designed and evaluated by using the OMNET simulation environment and Inet4 framework. The simulation results are shown by the evaluation methods used (delay, throughput, packets sent, and packets received). These results proved the success of the architectural work that was implemented in the system.

Wireless Visual Sensor Networks (WVSNs) are a branch of Wireless Sensor Networks (WSNs), WVSN nodes vary from standard WSN nodes in the ability of sensing the environment in two dimensions rather than in one. Therefore, it follows the three main fundamentals of WSNs: wireless networking, distributed sensing and low power hardware. This paper discusses different challenges that face the design of WVSNs like deployment of nodes, field of view overlapping, image analysis, area coverage and energy consumption. Efforts have been done mainly to survey the problem of energy consumption that can affect the lifetime of visual sensor network and overview the different techniques that have been used by many researchers to handle this crucial issue.