R. Kamaruddin

Toward Optical Sensors: Review and Applications

Recent advances in fiber optics (FOs) and the numerous advantages of light over electronic systems have boosted the utility and demand for optical sensors in various military, industry and social fields. Environmental and atmospheric monitoring, earth and space sciences, industrial chemical processing and biotechnology, law enforcement, digital imaging, scanning, and printing are exemplars of them. The ubiquity of photonic technologies could drive down prices which reduced the cost of optical fibers and lasers. Fiber optic sensors (FOSs) offer a wide spectrum of advantages over traditional sensing systems, such as small size and longer lifetime. Immunity to electromagnetic interference, amenability to multiplexing, and high sensitivity make FOs the sensor technology of choice in several fields, including the healthcare and aerospace sectors. FOSs show reliable and rigid sensing tasks over conventional electrical and electronic sensors. This paper presents an executive review of optical fiber sensors and the most beneficial applications.

Path Loss Analysis of WSN Wave Propagation in Vegetation

Deployment of a successful wireless sensor network requires precise prediction models that provide a reliable communication links of wireless nodes. Prediction models fused with foliage models provide sensible parameters of wireless nodes separation distance, antenna height, and power transmission which affect the reliability and communication coverage of a network. This paper review the line of sight and the two ray propagation models combined with the most known foliage models that cover the propagation of wireless communications in vegetative environments, using IEEE 802.15.4 standard. Simulation of models is presented and the impacts of the communication parameters, environment and vegetation have been reported.

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.

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.