527 research outputs found

    Improved detection of Probe Request Attacks : Using Neural Networks and Genetic Algorithm

    Get PDF
    The Media Access Control (MAC) layer of the wireless protocol, Institute of Electrical and Electronics Engineers (IEEE) 802.11, is based on the exchange of request and response messages. Probe Request Flooding Attacks (PRFA) are devised based on this design flaw to reduce network performance or prevent legitimate users from accessing network resources. The vulnerability is amplified due to clear beacon, probe request and probe response frames. The research is to detect PRFA of Wireless Local Area Networks (WLAN) using a Supervised Feedforward Neural Network (NN). The NN converged outstandingly with train, valid, test sample percentages 70, 15, 15 and hidden neurons 20. The effectiveness of an Intruder Detection System depends on its prediction accuracy. This paper presents optimisation of the NN using Genetic Algorithms (GA). GAs sought to maximise the performance of the model based on Linear Regression (R) and generated R > 0.95. Novelty of this research lies in the fact that the NN accepts user and attacker training data captured separately. Hence, security administrators do not have to perform the painstaking task of manually identifying individual frames for labelling prior training. The GA provides a reliable NN model and recognises the behaviour of the NN for diverse configurations

    Achieving Optimal Performance and Quality in LAN and WLAN for Mission-Critical Applications

    Get PDF
    © 2024 The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. This is the accepted manuscript version of a conference paper which has been published in final form at https://doi.org/10.1007/978-981-99-6974-6_17Voice Over Internet Protocol (VoIP) properties are vital for its reliability in mission-critical applications. This research aims to find network topology, call signalling and voice codecs property combinations that meet reliability targets of VoIP communication in a Small Office Home Office (SOHO) environment where network resources may be limited but reliable and secured operation is essential. Local Area Network (LAN) and Wireless LAN (WLAN) scenarios are evaluated using Quality of Service (QoS) and Mean Opinion Score (MOS) measurements to find which property combinations satisfy predefined classes; best quality and best performance. The research extended Roslin et al. [1] on LAN VoIP to WLANs, and validated Khiat et al. [2] s and Guy [3]’s work that argued SIP was effective in optimal set up. This research found that VoIP combinations offer some desirable characteristics, but at the cost of other properties required, leading to categorisation being based on the interpretation of the results, concluding that though, not ideal for mission-critical applications, combinations function well in replicating real-world scenarios. The analysis also established VoIP's scalability for application-based configurations, impact of VoIP’s modularity and ease of configuration in achieving user expectations. Further property testing can solidify VoIP’s capabilities to function for mission-critical environments

    ENVIRONMENTAL IMPACTS OF THE PROPOSED BADDEGEDERA IMPOUNDING RESERVOIR

    Get PDF
    The alternative sources of water available for the consumers in the project area coveringTalpc. Habaraduwa. Koggala EPZ and coastal belt. Ahangama, Dikkumbura and Irnaduwaarc ground water. or surface water Irorn Gin ganga, Nilwala ganga or the proposeduupounding reservoir at Baddcgcdara.The first choice on the basis of water quality and treatment costs was ground water, hut aftera test drilling program this source was found to he inadequate.The proposed impounding reservoir at Baddegcdara is located near to the project area andtechnical Icasibility studies revealed that this is a feasible proposal.Posiuvc and negative environmental impacts of the proposed project were identified usingan environmental interaction matrix and it was attempted to evaluate the overall impactLlsing the Battelle's Environmental Evaluation System. Weights for the different impactswen: assigned depending on the relative importance of the impacts. Value functions forSOIllC of the impacts were developedThe topography of the area docs not lend itself 10 the fashioning of a deep lake. According10 past studies. it has been showed that the ideal wild life lake is shallow with gently slopingshore». This type of situation could he expected from the proposed impoundment. Thesenatural qualities or the habitat could be further augmented by various managementtechniques such as the restriction or the area or impoundment and catchment.

    Enhancing WPA2-PSK four-way handshaking after re-authentication to deal with de-authentication followed by brute-force attack a novel re-authentication protocol

    Get PDF
    The nature of wireless network transmission and the emerging attacks are continuously creating or exploiting more vulnerabilities. Despite the fact that the security mechanisms and protocols are constantly upgraded and enhanced, the Small Office/Home Office (SOHO) environments that cannot afford a separate authentication system, and generally adopt the IEEE 802.11 Wi-Fi-Protected-Access-2/Pre-Shared-Key (WPA2-PSK) are still exposed to some attack categories such as de-authentication attacks that aim to push wireless client to re-authenticate to the Access Point (AP) and try to capture the keys exchanged during the handshake to compromise the network security. This kind of attack is impossible to detect or prevent in spite of having an Intrusion Detection and Prevention System (IDPS) installed on the client or on the AP, especially when the attack is not repetitive and is targeting only one client. This paper proposes a novel method which can mitigate and eliminate the risk of exposing the PSK to be captured during the re-authentication process by introducing a novel re-authentication protocol relying on an enhanced four-way handshake which does not require any hardware upgrade or heavy-weight cryptography affecting the network flexibility and performances

    Enhancing WPA2-PSK four-way handshaking after re-authentication to deal with de-authentication followed by brute-force attack a novel re-authentication protocol

    Get PDF
    The nature of wireless network transmission and the emerging attacks are continuously creating or exploiting more vulnerabilities. Despite the fact that the security mechanisms and protocols are constantly upgraded and enhanced, the Small Office/Home Office (SOHO) environments that cannot afford a separate authentication system, and generally adopt the IEEE 802.11 Wi-Fi-Protected-Access-2/Pre-Shared-Key (WPA2-PSK) are still exposed to some attack categories such as de-authentication attacks that aim to push wireless client to re-authenticate to the Access Point (AP) and try to capture the keys exchanged during the handshake to compromise the network security. This kind of attack is impossible to detect or prevent in spite of having an Intrusion Detection and Prevention System (IDPS) installed on the client or on the AP, especially when the attack is not repetitive and is targeting only one client. This paper proposes a novel method which can mitigate and eliminate the risk of exposing the PSK to be captured during the re-authentication process by introducing a novel re-authentication protocol relying on an enhanced four-way handshake which does not require any hardware upgrade or heavy-weight cryptography affecting the network flexibility and performances

    Post-Disaster Housing Reconstruction in Sri Lanka: What Methodology?

    Get PDF
    Research methodology is the procedural framework within which the research is conducted. This includes the overall approach to a problem that could be put into practice in a research process, from the theoretical underpinning to the collection and analysis of data. Choice of methodology depends on the primary drivers: topic to be researched and the specific research questions. Hence, methodological perspectives of managing stakeholder expectations of PDHR context are composed of research philosophies, research strategy, research design, and research techniques. This research belonged to social constructivism or interpretivism within a philosophical continuum. The nature of the study was more toward subjectivism where human behavior favored voluntary stance. Ontological, methodological, epistemological, and axiological positioning carried the characteristics of idealism, ideographic, anti-positivism, and value laden, respectively. Data collection comprises two phases, preliminary and secondary. Exploratory interviews with construction experts in the United Kingdom and Sri Lanka were carried out to refine the interview questions and identify the case studies. Case study interviews during the secondary phase took place in Sri Lanka. Data collected at the preliminary stage were used to assess the attributes of power, legitimacy/proximity, and urgency of stakeholders to the project using Stakeholder Circle™ software. Moreover, the data collected at secondary phase via case studies will be analyzed with NVivo 8. This article aims to discuss these methodological underpinnings in detail applied in a post-disaster housing reconstruction context in Sri Lanka

    Impact of culture towards disaster risk reduction

    Get PDF
    Number of natural disasters has risen sharply worldwide making the risk of disasters a global concern. These disasters have created significant losses and damages to humans, economy and society. Despite the losses and damages created by disasters, some individuals and communities do not attached much significance to natural disasters. Risk perception towards a disaster not only depends on the danger it could create but also the behaviour of the communities and individuals that is governed by their culture. Within this context, this study examines the relationship between culture and disaster risk reduction (DRR). A comprehensive literature review is used for the study to evaluate culture, its components and to analyse a series of case studies related to disaster risk. It was evident from the study that in some situations, culture has become a factor for the survival of the communities from disasters where as in some situations culture has acted as a barrier for effective DRR activities. The study suggests community based DRR activities as a mechanism to integrate with culture to effectively manage disaster risk

    Needle to needle robot-assisted manufacture of cell therapy products

    Get PDF
    Advanced therapeutic medicinal products (ATMPs) have emerged as novel therapies for untreatable diseases, generating the need for large volumes of high-quality, clinically-compliant GMP cells to replace costly, high-risk and limited scale manual expansion processes. We present the design of a fully automated, robot-assisted platform incorporating the use of multiliter stirred tank bioreactors for scalable production of adherent human stem cells. The design addresses a needle-to-needle closed process incorporating automated bone marrow collection, cell isolation, expansion, and collection into cryovials for patient delivery. AUTOSTEM, a modular, adaptable, fully closed system ensures no direct operator interaction with biological material; all commands are performed through a graphic interface. Seeding of source material, process monitoring, feeding, sampling, harvesting and cryopreservation are automated within the closed platform, comprising two clean room levels enabling both open and closed processes. A bioprocess based on human MSCs expanded on microcarriers was used for proof of concept. Utilizing equivalent culture parameters, the AUTOSTEM robot-assisted platform successfully performed cell expansion at the liter scale, generating results comparable to manual production, while maintaining cell quality postprocessing

    Birds Learn Socially to Recognize Heterospecific Alarm Calls by Acoustic Association

    Get PDF
    Animals in natural communities gain information from members of other species facing similar ecological challenges [1, 2, 3, 4, 5], including many vertebrates that recognize the alarm calls of heterospecifics vulnerable to the same predators [6]. Learning is critical in explaining this widespread recognition [7, 8, 9, 10, 11, 12, 13], but there has been no test of the role of social learning in alarm-call recognition, despite the fact that it is predicted to be important in this context [14, 15]. We show experimentally that wild superb fairy-wrens, Malurus cyaneus, learn socially to recognize new alarm calls and can do so through the previously undemonstrated mechanism of acoustic-acoustic association of unfamiliar with known alarm calls. Birds were trained in the absence of any predator by broadcasting unfamiliar sounds, to which they did not originally flee, in combination with a chorus of conspecific and heterospecific aerial alarm calls (typically given to hawks in flight). The fairy-wrens responded to the new sounds after training, usually by fleeing to cover, and responded equally as strongly in repeated tests over a week. Control playbacks showed that the response was not due simply to greater wariness. Fairy-wrens therefore learnt to associate new calls with known alarm calls, without having to see the callers or a predator. This acoustic-acoustic association mechanism of social learning could result in the rapid spread of alarm-call recognition in natural communities, even when callers or predators are difficult to observe. Moreover, this mechanism offers potential for use in conservation by enhancing training of captive-bred individuals before release into the wild

    ASSESSMENT OF BIODIVERSITY IN THE MUTHURAJAWELA WETLAND SANCTUARY

    Get PDF
    Muthurajawela wetland. located as the west coast of Sri Lanka is the largestcoastal peal bag of the island. At present. the biodiversity of Muthurajawela isthreatened by unplanned development activities and growing human population.Therefore, an ecological survey was carried out in order to assess the presentstatus of biodiversity in Muthurajawela, and also to identify critical habitats forthe conservation and sustence of biodiversity. Field monitoring of fauna and florawas carried out at fortnightly intervals, using scientifically accepted rapidbiodiversity assessment techniques (fauna - line transects; flora - plots, Braun-Blanquet cover), The data was analysed using ecological indices(diversity/species richness), and critical habitats were identified using avifauna asa correlate of biodiversity. Ground truthing of vegetation maps was carried out todocument changes of major vegetation communities.The study enabled to identify 192 species of flora, distributed over seven majorvegetation communities at Muthurajawela; marsh, lentic flora, reed swamp, shortgrassland, scrubland, stream bank flora and mangrove swamp. The vertebratefauna documented included 40 species of fish, 14 species of amphibians, 31species of reptiles, 102 species of birds and 22 species of mammals. Among thetotal vertebrate species documented, 17 are endemic, 26 are considered asnationally threatened, while 36 are new records to Muthurajawela. The selectedinvertebrate species documented consisted of 48 species of butterflies and 22species odonates, the latter which turned out to be a useful indicator of habitatquality. The threats documented included direct exploitation (poaching, cutting oftrees), habitat degradation/modification (land reclamation, dumping of garbage,clearing of natural vegetation, pollution and eutrophication) and the spread ofseveral alien invasive species (including unmanaged domestic animals). Thenorthern part of the marsh serve as an ecotone, with a mixture of the above plantcommunities/habitat types which were relatively undisturbed. Analysis carriedout using ecological indices highlighted the northern region as a high biodiversityzone, which is critical for the conservation and future sustenance of biodiversity atMuthurajawela. Ground truthing of vegetation maps, supported with results of thevegetation survey showed that the composition of dominant flora has changedover a period of 10 years, in most places in the Muthurajawela Wetland, as aresult of human disturbances. Data on the avifauna also highlighted aconsiderable decrease in migrant birds at Muthurajawela, possibly due to habitatdeterioration.The findings have important conservation and managementimplications, in particular greater emphasis need to be placed on the more ciritcalareas of the marsh. An important policy implication would be the need
    corecore