Self-Addressable Memory-Based FSM: A Scalable Intrusion Detection Engine

One way to detect and thwart a network attack is to compare each incoming packet with predefined patterns, also called an attack pattern database, and raise an alert upon detecting a match. This article presents a novel pattern-matching engine that exploits a memory-based, programmable state machine to achieve deterministic processing rates that are independent of packet and pattern characteristics. Our engine is a self-addressable memory-based finite state machine (SAMFSM), whose current state coding exhibits all its possible next states. Moreover, it is fully reconfigurable in that new attack patterns can be updated easily. A methodology was developed to program the memory and logic. Specifically, we merge non-equivalent states by introducing super characters on their inputs to further enhance memory efficiency without adding labels. SAM-FSM is one of the most storage-efficient machines and reduces the memory requirement by 60 times. Experimental results are presented to demonstrate the validity of SAM-FSM

Asistencia de liquidez en el sistema financiero paralelo

El presente trabajo involucra un examen en profundidad de un conjunto de eventos que tuvieron lugar entre los años 2007 y 2008 en el sistema financiero paralelo —más conocido como shadow banking—, los cuales formaron parte crucial en el desarrollo de lo que la literatura especializada considera la peor crisis económica y financiera de las economías de mercado desde la Gran Depresión. Asimismo, también se analizarán en detalle las respuestas que el regulador —fundamentalmente la Reserva Federal de los Estados Unidos— debió improvisar con el objetivo de con-tener el pánico que se apoderó de los mercados financieros hacia finales de agosto de 2008. El trabajo pretende demostrar que aun cuando varios de los programas y facilidades de liquidez establecidos con el fin de asistir financieramente a las instituciones del sistema financiero paralelo eran susceptibles de críticas legales de acuerdo al marco jurídico entonces vigentes, los mismos constituían una legítima expresión de la autoridad conocida como “prestamista de última instancia”, la cual corresponde exclusivamente a los bancos centrales. El trabajo concluye remarcando la necesidad de dotar de un marco legal claro para la viabilizar la asistencia de liquidez de emergencia a las instituciones que se hallan por fuera sistema bancario tradicional, realizando a su vez un examen crítico de la reciente normativa en la materia, la cual obstaculiza deliberadamente la posibilidad de una respuesta temporánea y adecuada por parte de la Reserva Federal a un episodio sistémico acontecido en mercados o instituciones pertenecientes al sistema financiero paralelo

PATTERN ENCODING ALGORITHMS AND INFORMATION MODELING METRICS FOR NETWORK QUALITY OF SERVICE

Networks are becoming increasingly complex, making network quality of service (QoS) an ongoing and difficult problem. Important QoS challenges include ensuring availability of services, privacy and accuracy of data and preventing data loss. These challenges can be addressed by providing effective security mechanisms that meet the scalability requirements of modern networks, environments for testing these mechanisms and providing metrics to measure and increase information quality especially in resource limited networks such as sensor networks. To meet these goals, we present several topics. First, to address the scalability problems of deep packet inspection (DPI) in network intrusion detection systems (NIDS), we theoretically characterize DFA in order to develop scalable pattern matching engines. Second, to keep up with the multi-gigabit rates of current and future networks and to increase DPI performance, we exploit the inter-stream parallelism of network traffic and the parallel processing capabilities of graphics processing units to create a multi-gigabit GPU based deep packet inspection engine. Third, we address the state explosion problem of multi-stride DFA and exploit intra-stream parallelism to achieve multiple Gb/s speeds of DPI on a single processor. Fourth, to evaluate large scale deployment of DPI we develop a software test-bed for evaluating worm containment systems. Lastly, we develop information quality metrics for sensor networks, and use these metrics to schedule sensor data collection and increase the quality of information

Systematic review of studies evaluating the broader economic impact of vaccination in low and middle income countries.

BACKGROUND: Most health economic evaluations of childhood vaccination only capture the health and short-term economic benefits. Measuring broader, long-term effects of vaccination on productivity and externalities could provide a more complete picture of the value of vaccines. METHOD: MEDLINE, EconLit and NHS-EED databases were searched for articles published between January 1990 and July 2011, which captured broader economic benefits of vaccines in low and middle income countries. Studies were included if they captured at least one of the following categories on broader economic impact: outcome-related productivity gains, behaviour-related productivity gains, ecological externalities, equity gains, financial sustainability gains or macroeconomic benefits. RESULTS: Twenty-six relevant studies were found, including observational studies, economic models and contingent valuation studies. Of the identified broader impacts, outcome-related productivity gains and ecological externalities were most commonly accounted for. No studies captured behaviour-related productivity gains or macroeconomic effects. There was some evidence to show that vaccinated children 8-14 years of age benefit from increased cognitive ability. Productivity loss due to morbidity and mortality was generally measured using the human capital approach. When included, herd immunity effects were functions of coverage rates or based on reduction in disease outcomes. External effects of vaccines were observed in terms of equitable health outcomes and contribution towards synergistic and financially sustainable healthcare programs. CONCLUSION: Despite substantial variation in the methods of measurement and outcomes used, the inclusion of broader economic impact was found to improve the attractiveness of vaccination. Further research is needed on how different tools and techniques can be used in combination to capture the broader impact of vaccination in a way that is consistent with other health economic evaluations. In addition, more country level evidence is needed from low and middle income countries to justify future investments in vaccines and immunization programs. Finally, the proposed broader economic impact framework may contribute towards better communication of the economic arguments surrounding vaccine uptake, leading to investments in immunization by stakeholders outside of the traditional health care sector such as ministries of finance and national treasuries

Online 1 H‐MRS measurements of time‐varying lactate production in an animal model of glioma during administration of an anti‐tumoral drug

International audienceThe aims of this study were to implement a magnetic resonance spectroscopy (MRS) protocol for the online profiling of subnanomolar quantities of metabolites sampled from the extracellular fluid using implanted microdialysis and to apply this protocol in glioma‐bearing rats for the quantification of lactate concentration and the measurement of time‐varying lactate concentration during drug administration. MRS acquisitions on the brain microdialysate were performed using a home‐built, proton‐tuned, microsolenoid with an active volume of 2 μL. The microcoil was placed at the outlet of the microdialysis probe inside a preclinical magnetic resonance imaging (MRI) scanner. C6‐bearing rats were implanted with microdialysis probes perfused with artificial cerebrospinal fluid solution and the lactate dehydrogenase (LDH) inhibitor oxamate. Microcoil magnetic resonance spectra were continuously updated using a single‐pulse sequence. Localized in vivo spectra and high‐resolution spectra on the dialysate were also acquired. The limit of detection and limit of quantification per unit time of the lactate methyl peak were determined as 0.37 nmol/√min and 1.23 nmol/√min, respectively. Signal‐to‐noise ratios (SNRs) of the lactate methyl peak above 120 were obtained from brain tumor microdialysate in an acquisition time of 4 min. On average, the lactate methyl peak amplitude measured in vivo using the nuclear magnetic resonance (NMR) microcoil was 193 ± 46% higher in tumor dialysate relative to healthy brain dialysate. A similar ratio was obtained from high‐resolution NMR spectra performed on the collected dialysate. Following oxamate addition in the perfusate, a monotonic decrease in the lactate peaks was observed in all animals with an average time constant of 4.6 min. In the absence of overlapping NMR peaks, robust profiling of extracellular lactate can be obtained online using a dedicated sensitive NMR microcoil. MRS measurements of the dynamic changes in lactate production induced by anti‐tumoral drugs can be assessed accurately with temporal resolutions on the order of minutes. The MRS protocol can be readily transferred to the clinical environment with the use of suitable clinical microdialysis probes. KEYWORDS glioblastoma, in vivo MRI and MRS, lactate, metabolite profiling, microcoil, microdialysi