The importance of the road infrastructure for the society could be compared with importance of blood vessels for humans. To ensure road surface quality it should be monitored continuously and repaired as necessary. The optimal distribution of resources for road repairs is possible providing the availability of comprehensive and objective real time data about the state of the roads. Participatory sensing is a promising approach for such data collection. The paper is describing a mobile sensing system for road irregularity detection using Android OS based smart-phones. Selected data processing algorithms are discussed and their evaluation presented with true positive rate as high as 90% using real world data. The optimal parameters for the algorithms are determined as well as recommendations for their application.

/pdf/real-time-pothole-detection-using-android-smartphones-with-149ajgpnzc.pdf

Real time pothole detection using Android smartphones with accelerometers

Development in the technology of sensor such as Micro Electro Mechanical Systems (MEMS), wireless communications, embedded systems, distributed processing and wireless sensor applications have contributed a large transformation in Wireless Sensor Network (WSN) recently. It assists and improves work performance both in the field of industry and our daily life. Wireless Sensor Network has been widely used in many areas especially for surveillance and monitoring in agriculture and habitat monitoring. Environment monitoring has become an important field of control and protection, providing real-time system and control communication with the physical world. An intelligent and smart Wireless Sensor Network system can gather and process a large amount of data from the beginning of the monitoring and manage air quality, the conditions of traffic, to weather situations. In this paper, we discuss and review wireless sensor network applications for environmental monitoring. In order to implement a good monitoring system, there are several requirements to be followed. From the studies, it has been proved to be an alternative way to replace the conventional method that uses men force to monitor the environment. It is also proven that these approaches can improve the system performance, provide a convenient and efficient method and can also fulfill functional requirements.

Wireless Sensor Network Applications: A Study in Environment Monitoring System

We consider managing the freshness of status updates sent from a source (such as a sensor) to a monitoring node. The time-varying availability of energy at the sender limits the rate of update packet transmissions. At any time, the age of information is defined as the amount of time since the most recent update was successfully received. An offline solution that minimizes not only the time average age, but also the peak age for an arbitrary energy replenishment profile is derived. The related decision problem under stochastic energy arrivals at the sender is studied through a discrete time dynamic programming formulation, and the structure of the optimal policy that minimizes the expected age is shown. It is found that tracking the expected value of the current age (which is a linear operation), together with the knowledge of the current energy level at the sender side is sufficient for generating an optimal threshold policy. An effective online heuristic, Balance Updating (BU), that achieves performance close to an omniscient (offline) policy is proposed. Simulations of the policies indicate that they can significantly improve the age over greedy approaches. An extension of the formulation to stochastically formed updates is considered.

Age of information under energy replenishment constraints

This paper utilizes smartphone sensing of vehicle dynamics to determine driver phone use, which can facilitate many traffic safety applications. Our system uses embedded sensors in smartphones, i.e., accelerometers and gyroscopes, to capture differences in centripetal acceleration due to vehicle dynamics. These differences combined with angular speed can determine whether the phone is on the left or right side of the vehicle. Our low infrastructure approach is flexible with different turn sizes and driving speeds. Extensive experiments conducted with two vehicles in two different cities demonstrate that our system is robust to real driving environments. Despite noisy sensor readings from smartphones, our approach can achieve a classification accuracy of over $90\%$ with a false positive rate of a few percent. We also find that by combining sensing results in a few turns, we can achieve better accuracy (e.g., $95\%$) with a lower false positive rate.

/pdf/sensing-vehicle-dynamics-for-determining-driver-phone-use-s5981cb4qq.pdf

Sensing vehicle dynamics for determining driver phone use

This paper describes WalkCompass, a system that exploits smartphone sensors to estimate the direction in which a user is walking. We find that several smartphone localization systems in the recent past, including our own, make a simplifying assumption that the user's walking direction is known. In trying to relax this assumption, we were not able to find a generic solution from past work. While intuition suggests that the walking direction should be detectable through the accelerometer, in reality this direction gets blended into various other motion patterns during the act of walking, including up and down bounce, side-to-side sway, swing of arms or legs, etc. Moreover, the walking direction is in the phone's local coordinate system (e.g., along Y axis), and translation to global directions, such as 45 degree North, can be challenging when the compass is itself erroneous. WalkCompass copes with these challenges and develops a stable technique to estimate the user's walking direction within a few steps. Results drawn from 15 different environments demonstrate median error of less than 8 degrees, across 6 different users, 3 surfaces, and 3 holding positions. While there is room for improvement, we believe our current system can be immediately useful to various applications centered around localization and human activity recognition.

/pdf/demo-i-am-a-smartphone-and-i-can-tell-my-user-s-walking-47j13scby2.pdf

Demo: I am a smartphone and i can tell my user's walking direction

Monitoring wild animals, especially those that are becoming endangered (for example, lynxes and wolves) is important for biology researchers. Solutions for the monitoring already exist; however, they all have drawbacks, such as limited range or lifetime, sensing modality, reporting delays, unreliability of operation. In this work we describe our experiences in designing an improved animal monitoring sensor system and low-level software for sensor node control and communication. The target animals for this particular research are wild lynxes or canines, however it can be extended to other animal species. The LynxNet system is based on tracking collars, built around TMote Mini sensor nodes, sensors, GPS and 433MHz radio, and stationary base stations, placed at the locations that are frequented by the animals. We present preliminary field results of our radio communication range tests.

/pdf/lynxnet-wild-animal-monitoring-using-sensor-networks-qdbsnjzhxa.pdf

LynxNet: wild animal monitoring using sensor networks

Time to deployment for wireless sensor networks could be reduced by using commercial sensor nodes. However, this may lead to suboptimal flexibility, power consumption and cost of the system. Our pilot deployment for precision agriculture and fruit growing research showed similar conclusions and outlined the design decisions leading to SADmote: a new sensor node for environmental monitoring. It was evaluated both in the lab and field, showing improved energy consumption over commercial solutions such as Tmote Sky and Waspmote.

/pdf/sadmote-a-robust-and-cost-effective-device-for-environmental-2t4b8p43hz.pdf

SADmote: a robust and cost-effective device for environmental monitoring

The most important advantages of RFID technology are transmitting and receiving of information wirelessly as well as low implementation and maintenance costs. Such attractive features are reason for widespread usage of RFID systems - from tracking of assets to measurement of the timing during sporting events. To ensure secure operation of such systems they should have appropriate protection against reverse engineering. The contribution of this paper is a method for reverse engineering of specific RFID system used for time measurements during sporting events. Selected communication protocol aspects are discussed and their replication with off-the-shelf hardware and software with the aim to simulate a non-existing RFID tag with certain self selected ID number are presented.

http://reinholds.zviedris.com/wiki/_media/mednis2012rfidcomm.pdf

Reinholds Zviedris

Papers

Real time pothole detection using Android smartphones with accelerometers

LynxNet: wild animal monitoring using sensor networks

SADmote: a robust and cost-effective device for environmental monitoring

RFID communication: How well protected against reverse engineering?