867 research outputs found
Quantitative Analysis of DoS Attacks and Client Puzzles in IoT Systems
Denial of Service (DoS) attacks constitute a major security threat to today's
Internet. This challenge is especially pertinent to the Internet of Things
(IoT) as devices have less computing power, memory and security mechanisms to
mitigate DoS attacks. This paper presents a model that mimics the unique
characteristics of a network of IoT devices, including components of the system
implementing `Crypto Puzzles' - a DoS mitigation technique. We created an
imitation of a DoS attack on the system, and conducted a quantitative analysis
to simulate the impact such an attack may potentially exert upon the system,
assessing the trade off between security and throughput in the IoT system. We
model this through stochastic model checking in PRISM and provide evidence that
supports this as a valuable method to compare the efficiency of different
implementations of IoT systems, exemplified by a case study
Distinguishing Observed Inattentive Behaviors in the College Classroom as they Correlate to Brain Wave Activity Utilizing a Wireless Electroencephalograph
A significant amount of research has been devoted to the behavioral correlates of inattention in children (A.P.A., 2000; Arnold, 2000; Gordon & Barkley, 1998). It is proposed by the authors that college students, in their several years of experience, are much more capable of masking these trademark behaviors. When a child loses interest they will begin to openly look around the room, shift in their seat, or chat with their neighbors (Sandberg, Rutter & Taylor, 1978; Arnold, 2000). College students however, are proposed to candidly fidget, shift in their seat, or even maintain eye contact with their instructor while “daydreaming”. Therefore, an additional physiological aid is required to better assess inattentive periods in college subjects. Given the invasive nature of past devices commonly used, such as the Electroencephalograph (EEG), accurate measurement proves to be very difficult in a natural setting (Boyd & Campbell, 1998). This study used a modified version of an EEG called the Attention Trainer (AT). The AT is smaller in size, and wireless thus alleviating distraction and allowing more reliable field assessment. The study found positive correlations (Table 1) between suggested and previously validated behaviors. Contrary to prior research, significant correlations were found between all four frequency bands (Beta, Theta, Delta, and SMR), suggesting the device may be inaccurate (Figure 1). While results can neither confirm nor discredit biofeedback applications for the AT, further research is needed for validation
Tardiglaciar y Postglaciar en la región mediterránea de la Península Ibérica (13500-8500 B.P.): transformaciones industriales y económicas
Alcoi archaeological Museum. 2000 report of activities.
Es resumeix l' activitar realitzada durant l' any 2000 i es descriuen els diferentes nivells d' actuació: administració i gestió, difusió. conservació i investigació.
Paraules clau: Activitat 2000. Visitans, Exposicions, Investigació, Museu Arqueológic Municipal d' Alcoi.In this report we give un abridged account of the activities carriecl out at the Museum during the year 2000, stanting its diferent levels of action, that is. Administration and Management. Publications and Knowledge spreading, preservation and research.
Key Words: Activities 2000 . Visitors. Exhibitions. Research. The Arqueological Museum of Alcoi (province of Alicante).Se resume la actividad realizada en el Museo durante el año 2000, describiéndose sus diferentes niveles de actuación: Administración y Gestión, la Difusión e Investigación.
Palabras claves: Actividades 2000; Visitantes. Exposiciones. Investigación, Museo Arqueológico Municipal de Alcoi (Alicante)
Alcoi archaeological Museum. 1993 report of activities.
S'hi resumeix l'activitat realitzada al Museu durant l'any 1993 i es descriuen els diferents nivells d'actuació: administració i gestió, difusió. conservació i investigació.In this report we give an abridged account of the activities carried out at the Museum during the year 1993, stanting its diferent levels of action, that is, Administration and Management. Publications and Knowledge spreading, preservation and Research.Se resume la actividad realizada en el Museo durante el año 1993, describiéndose sus diferentes niveles de actuación: Administración y
Gestión, la Difusión. Conservación e Investigación
Museu Arqueològic Municipal d'Alcoi Camil Visedo i Moltó.
Es resumeix l’activitat realitzada al Museu durant l’any 1996 i es descriuen els diferents nivells d’actuació: administració i gestió, difusió, conservació i investigació
Fallos de la regulación y su incidencia en la comercialización minorista de energía y las tarifas finales cobradas a los usuarios residenciales en el departamento de Antioquia, 1997-2005
En el presente trabajo, se pretende analizar los aspectos referentes a la regulación y su incidencia en el Mercado Minorista de Energía, específicamente el caso de la Fórmula Tarifaria General establecida por la Resolución CREG 031 de 1997, a través de la cual se determina el Costo Unitario de Prestación del Servicio, que sirve como referencia para la determinación de las tarifas a los usuarios finales por parte de todos los comercializadores, y su efecto en el precio final cobrado a los usuarios residenciales, principalmente los del Departamento de Antioquia.64 p.Contenido parcial: Generalidades del sector eléctrico colombiano -- La regulación de servicios públicos -- Mecanismos de regulación -- La tarifa óptima -- Mercado minorista eléctrico -- Modelos de competencia minorista
Observation of a valence transition in (Pr,Ca)CoO3 cobaltites: charge migration at the metal-insulator transition
X-ray absorption spectroscopy measurements in Pr0.5Ca0.5CoO3 and
(Pr,Y)0.55Ca0.45CoO3 compositions reveal that the valence of praseodymium ions
is stable and essentially +3 (Pr [4f 2]) in the metallic state, but abruptly
changes when carriers localize approaching the oxidation state +4 (Pr [4f 1]).
This mechanism appears to be the driving force of the metal-insulator
transition. The ground insulating state of Pr0.5Ca0.5CoO3 is an homogeneous
Co3.5-d state stabilized by a charge transfer from Pr to Co sites: 1/2Pr3+ +
Co3.5 \to 1/2Pr3+2d + Co3.5-d, with 2d \approx 0.26 e-.Comment: Submitted. 14 pages, 4 Figure
HIV Infection among Young People in Northwest Tanzania: The Role of Biological, Behavioural and Socio-Demographic Risk Factors.
BACKGROUND: Young people are at high risk of HIV and developing appropriate prevention programmes requires an understanding of the risk factors for HIV in this age group. We investigated factors associated with HIV among participants aged 15-30 years in a 2007-8 cross-sectional survey nested within a community-randomised trial of the MEMA kwa Vijana intervention in 20 rural communities in northwest Tanzania. METHODS: We analysed data for 7259(53%) males and 6476(47%) females. Using a proximate-determinant conceptual framework and conditional logistic regression, we obtained sex-specific Odds Ratios (ORs) for the association of HIV infection with socio-demographic, knowledge, behavioural and biological factors. RESULTS: HSV-2 infection was strongly associated with HIV infection (females: adjOR 4.4, 95%CI 3.2-6.1; males: adjOR 4.2, 95%CI 2.8-6.2). Several socio-demographic factors (such as age, marital status and mobility), behavioural factors (condom use, number and type of sexual partnerships) and biological factors (blood transfusion, lifetime pregnancies, genital ulcers, Neisseria gonorrhoeae) were also associated with HIV infection. Among females, lifetime sexual partners (linear trend, p<0.001), ≥2 partners in the past year (adjOR 2.0, 95%CI 1.4-2.8), ≥2 new partners in the past year (adjOR 1.9 95%CI 1.2, 3.3) and concurrent partners in the past year (adjOR 1.6 95%CI 1.1, 2.4) were all associated with HIV infection. CONCLUSIONS: Efforts must be intensified to find effective interventions to reduce HSV-2. Effective behavioural interventions focusing on reducing the number of sexual partnerships and risk behaviour within partnerships are also needed. An increase in risky sexual behaviour may occur following marriage dissolution or when a young woman travels outside of her community and interventions addressing the needs of these subgroups of vulnerable women may be important. TRIAL REGISTRATION: ClinicalTrial.gov NCT00248469
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