M. S. Salim

New empirical path loss model for wireless sensor networks in mango greenhouses

FSPL and 2-Ray models are inaccurate to be used in conjugation with foliage models to predicted total path loss in vegetation environments and it has (38.20% and 65.74%) MPAE.The path loss model based COST235 and FSPL was the best performance to the empirical measurements, but its still not optimum due to that the MAPE was 10.69%.New empirical path loss model (LRCFM) for mango greenhouse has MAPE about 2.75% as compared to other models. Signal propagation losses in protected environments are investigated using wireless sensor networks (WSNs) based on the IEEE 802.15.4 standard of operating frequency, 2.425GHz. In this research, various empirical measurements were conducted to examine the effects of each part of a tree on path loss using different transceiver heights. A new linear path loss regression curve-fitting model (LRCFM) was derived based on the regression technique of computing the total path loss inside the greenhouse environment. The greatest vegetation effects appear within 1.5m tree height; in this research, this height was adopted to study and analyse vegetation models in a mango greenhouse. This research proves that path loss prediction based on free space path loss (FSPL) and two-ray (2-Ray) propagation models is inaccurate in predicting loss in certain environments, as these approaches are simplistic and optimistic. Thus, most known foliage models used in conjugation with FSPL and 2-Ray are inaccurate in predicting the total path loss in a greenhouse environment. The analytical and empirical results prove that the new derived model, the LRCFM, is the best candidate compared to other foliage models. The mean absolute percentage error (MAPE) of the total path loss based on the new LRCFM model was 2.7% compared to the 10.69% of the well-known models.

Wireless sensor actor networks

Recent advances in science and technology have led to facilitate monitoring the environment, collecting data, processing the sensed data, threshold-decision making process and lastly performing of suitable actions by using of distributed wireless sensor network and actor network. Wireless sensor actor network (WSAN) composed of a combination of at least one coordinator node with sensors and actor nodes that communicate wirelessly to perform a specified sensing, monitoring and actuation tasks. These technologies of sensing and acting are very promising in many fields such as agriculture and environment monitoring. Greenhouses fused with WSANs for crops mentoring and climate parameters control provides effective solution for enhance crops growth and prevent diseases. This paper explores WSAN definition, uniqueness and the main design concepts and applications. A detail exploring of agriculture applications has been presented. WSAN contributions for agricultural applications also have been presented.

Towards smart wireless sensor actor networks: Design factors and applications

Wireless sensor actor network (WSAN) adverts to the combination of mainly one coordinator node with two types of network nodes: sensors and actor nodes that communicate wirelessly to perform allotted sensing, monitoring and actuation chores. To provide effective and reliable WSAN performance, the coordinator node of a WSAN must be able to administrate the network, sensing nodes and synchronize the actor actions with appropriate commands order based on data gathered momently by sensing tasks. The latest advances in technologies have led to advances in monitoring the environment, collecting data, processing the sensed data, threshold-decision making process and lastly performing of suitable actions. This batch of processes could be carried out with distributed wireless sensor network and actor network, which yields a wireless sensor actor network (WSAN). This paper explores WSAN definition, uniqueness and the main design concepts and applications. A detail comparison of WSAN and ad hoc network also presented.

Wireless Sensor Network Wave Propagation in Vegetation

The Wireless Sensor Network (WSN) total path losses of a greenhouse based on the two popular empirical vegetation attenuation models are used to predict the connectivity and the maximum coverage of wireless nodes within the communication path. The foliage imposed effect on the propagating waves is examined, simulated and the total path losses concluded as a function of antenna height and a separation distance of WSN nodes in a field of various densities of vegetation inside a greenhouse. The implemented library of foliage propagation model can be embedded easily with other WSN simulator platforms. The best antennas height based on greenhouse environment and total path loss is shown to be with the 3.5 m and 1 m height for transceivers of main and end nodes, where less total path loss is obtained and perfect connectivity of (100 %) when used with MED vegetation models for all vegetation depths, less than 50 m, while ITU model shows perfect connectivity for same height combination but with less foliage depth of 40 m while it shows 88 % connectivity for higher foliage depth than 40 m.

Fiber Optic Sensors: Short Review and Applications

An extensive review of optical fiber sensors and the most beneficial applications is presented in this chapter. Although electrical sensing technologies have been successfully deployed in countless applications, the introduction of optical sensing, engineers and scientists can now perform measurements that were previously impractical or, in some cases, impossible with conventional electrical sensors. At present, many real-world applications already use both approaches to combine both benefits. The inherent advantages of fiber optic sensors such as lightweight, small size, passive, low attenuation, immunity to electromagnetic interference (EMI), wide bandwidth and environmental ruggedness were heavily used to offset their major disadvantages of high cost. Thus Fiber optic sensors (FOSs) have boosted the utility and demand for optical sensors in various military, industry and social fields. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors.

Optimization of Power Consumption for Centrifugation Process Based on Attenuation Measurements

The main objective of this research is to produce a mathematical model that allows decreasing the electrical power consumption of centrifugation process based on attenuation measurements. The centrifugation time for desired separation efficiency may be measured to determine the power consumed of laboratory centrifuge device. The power consumption is one of several parameters that affect the system reliability and productivity. Attenuation measurements of wave propagated through blood sample during centrifugation process were used indirectly to measure the power consumption of device. A mathematical model for power consumption was derived and used to modify the speed profile of centrifuge controller. The power consumption model derived based on attenuation measurements has successfully save the power consumption of centrifugation process keeping high separation efficiency. 18kW.h monthly for 100 daily time device operation had been saved using the proposed model.

Reduction of Power Consumption for Centrifugation Process Using Separation Efficiency Model

The power consumption, capacity, speed of rotation, separation precision and the centrifugation time are essential technical parameters of the centrifuge device, and hence their reliability may affect the system reliability and productivity. The modified period of velocity profile model (spinning period) which leads to decreasing the power consumption of laboratory centrifuge devices is derived. Based on the centrifugation time model, a fuzzy controller is proposed for the laboratory centrifuge device. The proposed controller design will produce high reliability by selecting various separation efficiencies, evaluating the separation efficiency period precisely, and reduction of separation power consumption. Based on the derived model, a low-cost controller modification leads to a shorter blood test time and lower power consumption while improving the separation efficiency to greater than 95 %.

A Wide Range Measurement and Disclosure of Ultrasonic Attenuation for Very Low Concentrations of Solid in Liquids Using Exponential Pulser Technique

The low solid concentrations in solutions are discovered and measured based on measurement the attenuation that occurs with a wave propagating through a fluid. Currently methods (Pitch-Catch, Pulse-echo and Immersion method) have some of weak points related with range of detection and power consumption, therefore, to increase the measuring range to include the detection of very low concentrations in solution as well as not relying on the material that the container is made of, a new technique for the pulser was designed to overcome the disadvantages of the three currently methods. This technique has been thoroughly applied to dispensing with the use of a container or reflector with a high reflection coefficient and Expanding the measuring range to include very low concentrations. The new technique demonstrates the system’s ability to distinguish the presence of particles in a fluid at a concentration lower than 10 %, which is below the limit of detection of the current method with the same device settings.

A New Ultrasound Pulser Technique for Wide Range Measurements

The objective of this research was to design and implement a new ultrasonic pulse-power-decay technique that transmits multiple ultrasound pulses through slurry to determine the lowest concentration that can provide an accurate attenuation measurement. A wide measurement range is obtained using the pulsed-power-decay transmission technique, and regardless of the material used to construct the container. A signal in the receiver transducer provides the attenuation measurements, for each echo, a fast Fourier transform (FFT) of the appropriate signal was obtained and compared with the water signals to yield the attenuation as a function of frequency. The data show the feasibility of measuring a kaolin concentration of 5% wt. When using a commercial pulser with the same device setting, no detectable echo was observed. Therefore, new technique measurements may prove useful in detecting solid content in liquid. This study demonstrated that the proposed pulsed-power transmission technique is promising for evaluating low concentrations of solids in fluids and for measuring sedimentation in solid-liquid systems.

Wireless sensor network wave propagation in vegetation: Review and simulation

Radio wave propagation through foliage medium induces an additional excess loss on the propagating components such as direct wave and reflected waves. Therefore to provide reliable and to enhance network coverage of wireless Sensor Actor Network (WSAN) a precise study and modeling of these effects must overcome with adequate prediction of the propagation loss of the WSAN signals. In this paper, the foliage imposed effect on the propagating waves is examined and the losses(dB) are concluded as a function of antenna height and the separation distance of wireless nodes in a field of various dense of foliage. Small distance low height, near ground, vegetated radio-wave propagation, the propagation loss is modeled by an integration of the foliage imposed effect and the effect from the radio wave reflections from the ground.