Location Aware Data Aggregation for Efficient Message Dissemination in Vehicular Ad Hoc Networks

An intelligent location-aware data aggregation mechanism for real-time observation, estimation, and efficient dissemination of any kind of traffic information in vehicular ad hoc networks (VANETs) is presented in this paper. The mechanism introduces a location awareness algorithm, enabling spatiotemporal database indexing and providing the location context of the messages without the use of advanced positioning systems such as satellite navigation and digital maps. Intelligent passive clustering and adaptive broadcasting are used to minimize the number of messages exchanged, packet collisions, and network load. The incoming messages are fused by a Kalman filter, allowing the description of the traffic-related information as a system characterized by as many variables as needed, depending on the application design. The scheme allows the comparison of aggregates and single observations, which enables their merging and better overall accuracy. Old information in aggregates is removed by real-time database refreshing, thus leaving only newer relevant information for the driver to make real-time decisions in traffic. The mechanism is generic and can be used for any kind of VANET information. It is evaluated by extensive simulations to show the efficiency and accuracy

Distributed Road Traffic Congestion Quantification Using Cooperative VANETs

The well-known traffic congestion problem in urban environments has negative impact on many areas including economy, environment, health and lifestyle. Recently, a number of solutions based on vehicle-to-vehicle communications were proposed for traffic congestion detection and management. In this paper we present an algorithm designed to enable each vehicle in the network to detect and quantify the level of traffic congestion in completely distributed way, independent of any supporting infrastructure and additional information such as traffic data from local authorities. Based on observations of traffic congestion by every vehicle, and by adapting the broadcast interval, it enables dissemination of the traffic information to other vehicles. The algorithm also makes every vehicle aware about the congestion level on the streets that are spatially separated from their current location by several streets. Its robustness keeps the vehicle's overall knowledge about congestion consistent, despite the short-term changes in vehicle's motion. Since the quantification of congestion is based on per-vehicle basis, the algorithm is able to operate even when only 10% of vehicles in the network are VANET enabled. Data aggregation and adaptive broadcasting are used to ensure that vehicles do not send redundant information about the traffic congestion. The simulations are conducted in Veins framework based on OMNeT++ network simulator and SUMO vehicular mobility simulator

Cultivation With Powdered Meteorite (NWA 1172) as the Substrate Enhances Low-Temperature Preservation of the Extreme Thermoacidophile Metallosphaera sedula

Recent studies have uncovered a vast number of thermophilic species in icy environments, permanently cold ocean sediments, cold sea waters, and cool soils. The survival of thermophiles in psychrobiotic habitats requires thorough investigation of the physiological and molecular mechanisms behind their natural cryopreservation. Such investigations are mainly impeded due to a restricted cultivation of thermophiles at low temperatures under the laboratory conditions. Artificial culture media used under the laboratory conditions usually fail to support cultivation of thermophiles at low-temperature range. In this study we cultivated the extreme thermoacidophilic archaeonMetallosphaera sedulawith the preliminary powdered and sterilized multimetallic extraterrestrial mineral material (the meteorite NWA 1172) under a low temperature regime in laboratory conditions. Our data indicate thatM. sedulawithstands cold stress and can be maintained at low temperatures, when supplemented with the meteorite NWA 1172 as the sole energy source. Cultivation with the meteorite NWA 1172 opens up new, previously unknown psychrotolerant characteristics ofM. sedula, emphasizing that culture conditions (i.e., the "nutritional environment") may affect the microbial survival potential in stress related situations. These observations facilitate further investigation of strategies and underlying molecular mechanisms of the survival of thermophilic species in permanently cold habitats

Milan Milojevic (Art Forum)

Milan Milojevic is head of printmaking at the Tasmanian School of Art. He discusses work made during a recent residency at COFA at UNSW, where he researched 18th and 19th century prints depicting the natural world

Host Based Intrusion Detection for VANETs: A statistical approach to Rogue Node Detection

In this paper, an intrusion detection system (IDS) for vehicular ad hoc networks (VANETs) is proposed and evaluated. The IDS is evaluated by simulation in the presence of rogue nodes (RNs) that can launch different attacks. The proposed IDS is capable of detecting a false information attack using statistical techniques effectively and can also detect other types of attacks. First, the theory and implementation of the VANET model that is used to train the IDS is discussed. Then, an extensive simulation and analysis of our model under different traffic conditions is conducted to identify the effects of these parameters in VANETs. In addition, the extensive data gathered in the simulations are presented using graphical and statistical techniques. Moreover, RNs are introduced in the network, and an algorithm is presented to detect these RNs. Finally, we evaluate our system and observe that the proposed application-layer IDS based on a cooperative information exchange mechanism is better for dynamic and fast-moving networks such as VANETs, as compared with other techniques available

Common fixed points for self-mappings on partial metric spaces

In this paper, we prove some results of a common fixed point for two self-mappings on partial metric spaces. Our results generalize some interesting results of Ilic et al. (Appl. Math. Lett. 24:1326-1330, 2011). We conclude with a result of the existence of a fixed point for set-valued mappings in the context of 0-complete partial metric spaces

Location aware data aggregation for efficient message dissemination in Vehicular Ad Hoc Networks

The main contribution of this thesis is the LA mechanism - an intelligent, locationaware data aggregation mechanism for real-time observation, estimation and efficient dissemination of messages in VANETs. The proposed mechanism is based on a generic modelling approach which makes it applicable to any type of VANET applications. The data aggregation mechanism proposed in this thesis introduces location awareness technique which provides dynamic segmentation of the roads enabling efficient spatiotemporal database indexing. It further provides the location context to the messages without the use of advanced positioning systems like satellite navigation and digital maps. The mechanism ensures that the network load is significantly reduced by using the passive clustering and adaptive broadcasting to minimise the number of exchanged messages. The incoming messages are fused by Kalman filter providing the optimal estimation particularly useful in urban environment where incoming measurements are very frequent and can cause the vehicle to interpret them as noisy measurements. The scheme allows the comparison of aggregates and single observations which enables their merging and better overall accuracy. Old information in aggregates is removed by realtime database refreshing leaving only newer relevant information for a driver to make real-time decisions in traffic. The LA mechanism is evaluated by extensive simulations to show efficiency and accuracy

Comparative Studies on the Reproductive and Productive Traits of New Hampshire and Sombor Crested Chicken Breeds Reared in Semi-Extensive Production System

Research was conducted on New Hampshire (in further text NH) and Sombor Crested (in further text SC) breeds which were kept in semi extensive system. 56 birds of each breed were used (50 females and 6 males) in the experiment. 100 eggs from every chicken breed were used for natural hatching, and remained eggs were sold. From the total number of the naturally incubated eggs, 83 (NH) and 85 (SC) chickens were hatched, and they were used for the study of performance and related parameters. Eggs and chickens originating from NH breed were statistically significantly heavier (P<0.001; P<0.01) compared with SC breed. Egg shape index and chicken percentage in egg weight were significantly higher at SC (P<0.001; P<0.05) compared to NH breed. Very strong positive correlation was determined between egg weight and chicken weight in both breeds. Very weak negative correlation was determined between egg weight and relative chicken intake in the egg weight. Similarly, between egg shape index and chicken weight, negative correlation coefficient was determined in both breeds. However, between egg shape index and chicken percentage, statistically significant (P<0.001) negative correlation coefficient was determined in NH breed. Significant (P<0.05) positive correlation for the same performances was determined in SC breed