Sinkholes Research Articles

Impact of Black Hole and Sink Hole Attacks on Routing Protocols for WSN

With the drastic growth of Internet and VLSI design, applications of WSNs are increasing tremendously that ranges from environmental monitoring, habitat monitoring, traffic surveillance to battle fields. In WSN a number of tiny sensor nodes managed by small batteries are deployed in a hostile environment to monitor the physical parameters. During transmission, the sensor nodes consume considerable amount of energy. There are many constraints on these sensor nodes such as limited memory, limited battery power, and limited processing capability. Moreover, these factors impose a restricted lifetime for the entire network. When sensor nodes send the information to the base station (BS), routing protocol plays the key role to deliver the information at the destination. Low Energy Adaptive Clustering Hierarchy (LEACH) and LEACH-C is the well-known distributed and centralized clustering routing protocol respectively. In LEACH, the cluster head (CH) is elected on a probabilistic threshold value on a rotation basis and only CHs are allowed to send the information to the BS. LEACH-C is the modified version of LEACH and works on the centralized principle. Further, WSNs are vulnerable to many types of attacks, as WSNs are normally deployed in a harsh environment. So, security is one of the major challenging issues that need to be focused. Many researchers have addressed these issues on LEACH protocol as LEACH is the first ever cluster based routing protocol. As far as our knowledge is concerned, there is a lack of research in the current literature by considering both LEACH and LEACH-C protocol under some attacks. So, we have made an attempt to analyze the performance of both the protocols under some well-known attacks like black hole and sink hole attacks. Again, we plan to propose a detection mechanism which is in progress.

Chinese karst geology and measures to prevent geohazards during shield tunnelling in karst region with caves

Karst landscapes are widely distributed in China, and buried karst is widespread in Guangdong. This study mainly focuses on buried karst or karst caves which are underground at depths of up to 50 m and can significantly affect engineering construction activity. The karst caves, which are widely distributed in Guangdong Province, have the following features: high fissure water content, high rock permeability, prone to collapse, variable shapes, and irregular distribution. When a shield tunnel is constructed in this kind of environment, hazards, such as sink holes, the ingress of water or stones, and damage to the constructed tunnels may occur. Thus, karst caves need to be treated before tunnel construction. This paper presents a procedure for karst cave treatment to mitigate possible hazards during shield tunnelling in karst regions. The construction procedure includes field investigation, judgment, treatment, and effectiveness check. The treatment criteria, grouting material, construction steps, and effectiveness check for the karst cave treatment are introduced in detail. A field test on shield tunnelling excavation was conducted using the karst cave treatment in the karst region of Guangzhou, China. Field investigations include testing the unconfined compressive strength (UCS) of borehole samples of grouting materials, standard penetration test (SPT), core recovery (CR), ground surface settlement and building settlement. All of the UCS values of the borehole samples are greater than 0.2 MPa, the modified SPT values are more than ten, and the CR values are greater than 90 %. The measured values of ground surface settlement and building settlement are all within the allowable ranges. All of the test results demonstrate the applicability of this treatment process in karst regions.

Hydrogeological problems of the Křtinský valley in the Moravian karst

The Výpustek cave is located in the middle part of the Moravian Karst, which is the most known, largest and most karsted area in the Czech Republic. Hydrogeology of the area is very interesting, surrounding terrain has greatly changed due to extensive changes in the last 100 years. Some swallow holes were blocked, others newly created

TFSR: trust factors evaluation-based secure routing protocol for wireless sensor network

Wireless sensor network (WSN) is an emerging technology, with tiny nodes to sense the data and collect it at sink node. The cryptographic techniques are not sufficient to ensure the security against blackhole, sink hole, DoS attacks, etc, as the nodes are deployed in open environment. Our main goal is to develop a trust-based secure communication system for WSN at network layer. We have identified various trust factors and developed a trust model for each trust factor to ensure security. We have proposed and analysed our trust factors evaluation-based secure routing (TFSR) protocol using network simulator NS2. The result shows that trust factors and trust models enhances secure communication in WSN for various possible attacks. The proposed model shows 96% of improvement, when alternative path for communication is available in the network. The result also shows total improvement of 30% to 35% in case of large networks.

Příspěvek k poznání fauny bezobratlých krasových závrtů v obhospodařované krajině v CHKO Moravský kras 1. díl: Carabidae (Coleoptera)

The epigeic fauna in the sink holes was studied using formaldehyde ground traps at 14-day intervals from April to October in 2002 and 2003. A total of 5 transects of traps have been installed within 5 selected areas of the northern part of the Moravian Karst. Areas within the district of Vilémovice, Lažánky and Ostrov near Macocha villages have been studied in particular. Sink holes have been selected on the basis of how they are probably influenced by human activities (types such as regularly mown sink holes within a thoroughly exploited field – 1, sink holes partially or totally overgrown by shrubs – 3 and 2, sink holes with fully developed trees – 4, sink holes within an intensely exploited meadow – 5.It was the aim of this study to determine the species composition of individual areas, numbers of individual species, differences among areas characterised by synoecological characteristics such as the dominance, Shannon-Wieneręs index of species diversity, equitability, Jaccardęs index of similarity and to try to express the degree of anthropogenic influence. Similarity of individual areas has also been evaluated by means of the cluster analysis (on the basis of the Jaccardęs index).Eudominant species were Abax parallelepipedus, Anchomenus dorsalis, Carabus ullrichi, Microlestes maurus, Poecilus cupreus and Pterostichus melanarius. Species such as Aptinus bombarda, Licinus depressus, Molops elatus and Syntomus obscuroguttatus were the most important ones. The highest and lowest values of the index of species diversity were found in the area No. 4, and 1 and 2, respectively. Equitability was the highest and the lowest in the area No. 4 and 1, respectively. According to the Jaccardęs index, areas No. 2 and 3, and No. 1 and 4 were the most and least similar ones, respectively. A total of 53.3%, 45.6% and 1.1% of species could, be classified as belonging to the group E, A and R, respectively. The group E represents eurytopic species inhabiting a large variety of habitats, the group A contains species of more or less natural habitats while in the group R there are species with the most narrow ecological valence. The highest index of community was in the area No. 4, while the lowest in the area No. 1.The total results and the evaluation of characteristics such as dominance, index of diversity, equitability, ecological bond to the habitat expressed by species classification of A, E or R and the index the carabid beetle community proves the fact that areas No. 4 and 5 are under the least anthropogenic influence.

Pseudogymnoascus destructans in Croatia confirmed

This article is the first confirmed report of the species Pseudogymnoascus destructans in Croatia. In April 2013, 18 bats were found dead in the winter hibernaculum of the Uviraljka swallow hole. All the dead bats were of the species Myotis myotis, and thus a possible Pd infection was suspected. DNA analysis of wing samples was conducted and sequence and phylogenetic analysis confirmed that samples of all carcasses were positive for P. destructans. These results are the first known record of this fungus in Croatia.

Rationale for flood prediction in karst endorheic areas

A large karst area of South-Eastern Italy (Puglia) is characterized by endorheic basins, whose runoff does not discharge into the sea but converges toward internal lowlands and infiltrates or flows into underground cave systems through swallow holes. In such environment whenever intense rainfall events cover large areas and rainfall intensity exceeds the discharge capacity of sinks and swallow holes, significant volumes of runoff are produced and stored on surface causing floods and risks for people and goods. Most of these sinks are often at the end of small independent basins delimited by weak divides and, whenever water storage exceeds the overflow threshold, runoff contributes to downstream areas and, in cascade, large areas may contribute to deepest lowlands.The observation of historical flood events suggests that in such areas traditional methods for the individuation of the design flood event, and in particular of critical rainfall duration, lack of applicability and the worst rainfall condition, for a fixed return time, should be searched accounting for soil hydraulic behaviour and groundwater dynamics. In this paper a rationale for the evaluation of the critical rainfall event and of the flood-prone area for given return period is proposed. A case study is presented showing that for high return period events a “multiple-reservoirs” mechanism is activated that affects the critical rainfall condition as well as the flood extent in the urban areas.

Mobile Agent Based Enhanced Security for Wireless Sensor Networks

Wireless sensor networks (WSNs) have attracted a lot of researchers due to their high potential in critical applications. WSNs are currently being employed in a variety of applications ranging from medical to military, and from home to industry. WSNs have unique constraints as compared to traditional networks making the implementation of existing security measures not practicable. These constraints are the result of limitations regarding the sensor nodes' memory, energy and transmission and processing power. So, traditional security mechanisms with large overhead of computation and communication are infeasible in WSNs. Thus, design and implementation of secure WSNs is challenging task. Recently mobile agents have been proved as an enabled technology for programming WSN. This research work fundamentally focuses on producing a combined security solution which uses mobile agents. The proposed security solution using mobile agents is to provide basic security services and to defend against seven attacks such as Denial of Service attack, Hello flooding attack, Traffic analysis, Cloning attack, Sink hole attack, Black hole attack and Selective forwarding attack with the energy overhead of addressing a single attack.

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The study area is located at the intersection of a karstic plateau basin in the Munzur Mountain range and a low-lying karstic discharge area in the Ovacik Plain. The mountain range extends east to west and the glacial plain runs parallel in similar direction. The research area is an excellent microcosm of a polygenic morphological karst system. The mountain terrain visible today is dramatic barren landscape and the by-product of multiple, interrelated processes, such as glaciations, karstification and tectonics. The insurgence waters cut into the sediment, gain velocity, and then disappear into a seven meter high by seven meter wide swallow hole cave entrance at 2600m. In the past, pre-Pleistocene dolines had helped transform this area into an icefield landscape. When glaciation period ended, karstic process revived again during Holocene and Kepir Cave has operated as a swallow hole again. The main factors of change can be attributed to glaciations in Pleistocene and intensified karstification during the Holocene. The thick stacking limestone or massif provides the geologic structure for underground drainage and the formation of what may be a significant and deep cave system. The cave system appears to be developing vertically along a prominent fault that is visible just inside the swallow hole entrance. The resurgence, Elbaba, must be related to the Ovacik Fault extending at the northern edge of Ovacik Plain. This karstic system continues to develop as an active system fed by significant snow and rain waters.

Novel Scheme of Fuzzy based Concealing Sink Node with Fake Holes (F-CSH)

Due to the sink node crucial position, its location privacy is becoming one of the major issues in wireless sensor networks (WSNs) which requires ultimate protection. Particularly, the WSNs successfulness is endanger as the wireless transmission nodes are susceptive to illicit tracing and detection. While privacy of the message can be ensured through encryption content, this paper formalizes a novel efficient privacy preserving scheme to secure sink node location. The aim is to keep the location privacy of the sink node from being tracked using the traffic flow passive analysis. F-CSH is based on the concealing of the location of the main sink using fake sink holes been elected using fuzzy score function. In addition, comprehensive simulations proved that the proposed scheme significantly upgrades both delivery time and conservation energy cost compared with existing strategies.

Spiders (Araneae) of selected sinkholes of Moravský kras Protected Landscape Area (Czech Republic)

In this study, we present faunistic data about spiders in selected sinkholes of northern part of Moravský kras Protected Landscape Area. Time of collection was established in the following terms: 24 March 2010 – 22 September 2010. We collected altogether 5742 adult specimens which were determined to 59 species of 14 families. We found two very rare spiders (critically endangered Porrhomma errans and endangered Walckenaeria monoceros) and several interesting, rarely collected bioindicator species (Alopecosa trabalis, Mecopisthes silus, Zelotes longipes). From the bioindicative evaluation point of view, 44% of found species belong to species with connection to natural habitats, 37% belong to species preferring semi-natural habitats, and 19% belong to species of disturbed habitats. From the relictness point of view, majority of species was of the expansive category (53%), 40% of class II relicts, and only 7% of class I relicts. Sink holes did not increase total biodiversity of agricultural land too much because of their relative small size.

A Novel Technique to Detect Intrusion in Manet

In this paper a novel technique has been proposed for intrusion detection in MANET, where agents are fired from a node for each node randomly and detect the defective nodes. Detection is based on triangular encryption technique (TE)[9,10], and AODV[1,2,3,8] is taken as routing protocol. The scheme is an ‘Agent’ based intrusion detection system. This technique is applied on two types of defective nodes namely packet sinking and black hole attack. For simulation purpose we have taken NS2 (2.33) and three type of parameters are considered. These are number of nodes, percentage of node mobility and type of defective nodes. For analysis purpose 20, 30, 30, 40, 50 and 60 nodes are taken with variability. Percentage of defectiveness as 10%, 20%, 30% and 40%.Packet sink and black hole attack are considered as defectiveness of nodes. We have considered generated packets, forward packets, average delay and drop packets as comparisons and performance analysis parameters.

A LEADER BASED MONITORING APPROACH FOR SINKHOLE ATTACK IN WIRELESS SENSOR NETWORK

Security is one of an important factor to be consid ered seriously in wireless sensor networks. In WSN, in many ways intrusion may occur, in the past decades there is no perfect IDS, without any wasting of resources like time, energy, cost and number of phy sical items. The main objective is to ensure the se curity and improve the quality of network by applying a Le ader based intrusion detection system in the Wirele ss Sensor Network (WSN). Here, we are focusing on the attack known as sinkhole attack which is considered as the biggest threat in wireless sensor network wh ich spoils the complete communication and a data lo ss between a pair of nodes as source node and a destin ation node. In order to provide a complete solution to detect and avoid sinkhole attack a Leader Based Int rusion Detection System (LBIDS) is proposed. In thi s approach a leader is elected for each group nodes w ithin the network, region wise and it do compares a nd calculates the behavior of every node, logically ex ecutes our detection module and monitors each node behaviour within the cluster for any sinkhole attac k to occur. When a node gets detected as a compromised node, it informs that nodes status to the other lea der within the WSN, so all the leaders in the netwo rk knows about the sink hole node information and the leaders stop communication with sinkhole Node.

Sinking and recirculation of large intruders in vertically vibrated granular beds

A series of experiments are described in which air-immersed grains within different containers are exposed to vertical vibrations. When the peak acceleration relative to gravity exceeded Γ=6 at 49Hz), tilted cavitating beds were formed. Then, when a large, low-density object was put onto the free surface, the vigorous granular convection dragged it into the bed. The large object was not being dragged into the bed at Γ>6 when the air pressure inside the container fell well below1Torr. These findings, as well as those from computer simulations, confirm the key role played by large air cavities such as swallow holes in submerging large, low-density objects into a granular bed.

Hazards and landscape changes (degradations) on Hungarian karst mountains due to natural and human effects

In order to study the karstological processes within the karst ecological system, the geohazards and degradation of karst landscapes on the karst areas of the Bakony mountains (Hungary), we investigated the abiotic elements of the environment, soil and cover deposits, erosion soil decay; the changes in the quantity and quality of karst waters: contamination at swallow holes, contamination of karst springs; and the biogenic factors: surface vegetation coverage by the corine land cover method, plant-ecological examinations, qualification of surface waters with the help of biological water labeling. We recognized that t he increasing human activities during the past few centuries have had significant impact on the investigated landscapes of karst areas because of their spatial sensitivity. In the scope of our research we concluded that the landscape changes due to natural and human effects can vary strongly on the different karst areas. These differences can arise from the climatic and geomorphologic situation, the cover-layer’s qualities, etc., but primarily from the different utilization of the investigated karst areas (e.g. the intensity, characteristics and territorial extension of utilization). On the spot investigation we detected traces of new and fast geomorphological processes (gully formation, landslides, collapses, new sinkhole development) and landforms (sinkholes, gullies, swallow holes), which are clear evidences of the effect of climatic changes.

Signal Strength based Hello Flood Attack Detection and Prevention in Wireless Sensor Networks

Wireless sensor network is a highly distributed network of small lightweight wireless sensor nodes, deployed in large numbers to monitor the environment or system. These sensor networks have limitations of system resources like battery power, radio range and processing capability. Low processing power and wireless connectivity make such networks vulnerable to various attacks like sink hole, black hole, Sybil attacks, selective forwarding, worm hole, hello flood etc. Among these hello flood attack is an important attack on the network layer, in which an adversary, which is not a legal node in the network, can flood hello request to any legitimate node using high transmission power and break the security of WSNs. The current solutions for this type of attack are mainly cryptographic, which suffer from heavy computational complexity. Hence these are less suitable in terms of memory and battery power. In this paper a method has been proposed to detect and prevent hello flood attack using signal strength of received Hello messages. Nodes have been classified as friend and stranger based on the signal strength of Hello messages sent by them. Nodes classified as stranger are further validated by sending a simple test packet; if the reply of test packet comes back in a predefined time then it is treated as valid otherwise it is treated as malicious. The algorithm is implemented in ns-2 by modifying the AODVrouting protocol. The performance of algorithm has been tested under different network scenarios. The simulation results show improved performance of the new algorithm in terms of number of packet delivery ratio as compare to AODV with hello flood attack.

Music piracy and digital rights management in Mexico: shifting to a sound model

Much has been written about piracy and the measures that industrialised countries have implemented to eliminate illegal music distribution and copyright infringement. Nevertheless, similar measures have been applied in second and third world countries with a different level of success. Mexico specifically, is appointed as a haven for piracy and a sink hole for intellectual property that is beyond repair, and which accounts for millions of dollars of loss to the copyright owners every year. Based on that premise, this document intends to analyse the effectiveness of the existing copyright enforcement measures and the music industry business model under the light of the socioeconomic and cultural panorama of this Latin American nation to determine, from a systemic perspective, where the leverage points for a so needed turn of events can be found.

Energy Efficient and Secure, Trusted network discovery for Wireless Sensor Networks

While routing Wireless Sensor nodes in the Multi-hop network ,nodes may undergo some attacks such as sink hole attack, worm hole attack, Sybil attack etc., by the attackers through identity deception. So, to secure WSN’s against attackers or hackers misdirecting the nodes in the network while routing, in our base paper we have designed and implemented TARF, a robust trust aware routing framework concept for dynamic for WSN’s. TARF provides trustworthy and energy-efficient route and also it provides security against all these attacks which are mentioned above. In our work, we are using modern technology like ECC i.e., Elliptic Curve Cryptography for encoding and decoding purpose. To know the performance of this TARF routing, in our paper we are comparing TARF Routing with Existing Routing and generating routing tables. To find the secure network discovery we are generating Combinatorial Key for Pre Key-Distribution in TARF Network. In the handheld devices like mobile we are trying to find the attacker information.

Occurrence and dynamics of micropollutants in a karst aquifer

Karst systems represent important yet vulnerable drinking water resources. A wide spectrum of pollutants may be released into karst groundwater from agriculture, livestock farming, private households, and industry. This work provides an overview on the occurrence and dynamics of micropollutants in a karst system of the Swiss Jura. Ten months of intensive monitoring for micropollutants confirmed that the swallow hole draining an agricultural plain was the main entry path for pesticides into the karst system and the two connected springs. Elevated fungicide concentrations in winter and occasional quantification of pharmaceuticals suggested wood- or façade treatment and domestic sewer as additional sources of contamination. A continuous atrazine signal in the low ng/L range might affect the autochthonous endokarst microbial community and represents a potential risk for the human population through karst groundwater.

Mollifying the Effect of Cloning, Sink Hole and Black Hole Attacksin Wireless Sensor Networks using Mobile Agents with Several Base Stations

dangerous attacks in wireless sensor network is handled in this proposed security solution. This paper proposes a lightweight and fast mobile agent technology based security solution against cloning attack, sinkhole attack and black hole attack for wireless sensor networks (WSNs).Recently mobile agents have been proposed in wireless sensor networks to reduce the communication cost especially over low bandwidth links. The proposed scheme is to defend against cloning attack, sink hole attacks and black hole attacks using mobile agents. In the cloning attack, adversary introduces replicas of compromised node. In the sinkhole attack, an adversary lures traffic through a compromised node. A black hole attack is a type of denial-of-service attack accomplished by dropping packets for a particular network destination in bulk (by dropping all packets).For dealing with black hole attacks more than one base station concept is also added with mobile agent concept to bring the best result. Here we implement a simulation-based model of our solution to recover from cloning attack, sinkhole attack and black hole attack in a Wireless Sensor Network. This mechanism does not require more energy.Comparison of communication overhead and cost were made between the proposed attack detection system using mobile agent against the security system in the absence of mobile agents. Comparison was also done between the proposed security system with the security system handling single attack. The mobile agents were developed using the Aglet.