Database Intrusion Detection: Defending Against the Insider Threat

Not only are Databases an integral and critical part of many information systems, they are critical information assets to many business enterprises. However, the network and host intrusion detection systems most enterprises use to detect attacks against their information systems cannot detect transaction-level attacks against databases. Transaction-level attacks often come from authorized users in the form of inference, query flood, or other anomalous query attacks. Insider attacks are not only growing in frequency, but remain significantly more damaging to businesses than external attacks. This paper proposes a database intrusion detection model to detect and respond to transaction-level attacks from authorized database users

Novel Approaches for Structural Health Monitoring

The thirty-plus years of progress in the field of structural health monitoring (SHM) have left a paramount impact on our everyday lives. Be it for the monitoring of fixed- and rotary-wing aircrafts, for the preservation of the cultural and architectural heritage, or for the predictive maintenance of long-span bridges or wind farms, SHM has shaped the framework of many engineering fields. Given the current state of quantitative and principled methodologies, it is nowadays possible to rapidly and consistently evaluate the structural safety of industrial machines, modern concrete buildings, historical masonry complexes, etc., to test their capability and to serve their intended purpose. However, old unsolved problematics as well as new challenges exist. Furthermore, unprecedented conditions, such as stricter safety requirements and ageing civil infrastructure, pose new challenges for confrontation. Therefore, this Special Issue gathers the main contributions of academics and practitioners in civil, aerospace, and mechanical engineering to provide a common ground for structural health monitoring in dealing with old and new aspects of this ever-growing research field

Breeding Analysis of Growth and Decay in Nonlinear Waves and Data Assimilation and Predictability in the Martian Atmosphere

The effectiveness of the breeding method in determining growth and decay characteristics of certain solutions to the Kortweg-de Vries (KdV) equation and the Nonlinear Schrödinger equation is investigated. Bred vectors are a finite amplitude, finite time generalization of Leading Lyapunov Vectors (LLV), and breeding has been used to predict large impending fluctuations in many systems, including chaotic systems. Here, the focus is on predicting fluctuations associated with extreme waves. The bred vector analysis is applied to the KdV equation with two types of initial conditions: soliton collisions, and a Gaussian distribution which decays into a group of solitons. The soliton solutions are stable, and the breeding analysis enables tracking of the growth and decay during the interactions. Furthermore, this study with a known stable system helps validate the use of breeding method for waves. This analysis is also applied to characterize rogue wave type solutions of the NLSE, which have been used to describe extreme ocean waves. In the results obtained, the growth rate maxima and the peaks of the bred vector always precede the rogue wave peaks. This suggests that the growth rate and bred vectors may serve as precursors for predicting energy localization due to rogue waves. Finally, the results reveal that the breeding method can be used to identify numerical instabilities. Effective simulation of diurnal variability is an important aspect of many geophysical data assimilation systems. For the Martian atmosphere, thermal tides are particularly prominent and contribute much to the Martian atmospheric circulation, dynamics and dust transport. To study the Mars diurnal variability (or thermal tides), the GFDL Mars Global Climate Model (MGCM) with the 4D-Local Ensemble Transform Kalman Filter (4D-LETKF) is used to perform a reanalysis of spacecraft temperature retrievals. We find that the use of a "traditional" 6-hr assimilation cycle induces spurious forcing of a resonantly-enhanced semi-diurnal Kelvin waves represented in both surface pressure and mid-level temperature by forming a wave 4 pattern in the diurnal averaged analysis increment that acts as a "topographic" stationary forcing. Different assimilation window lengths in the 4D-LETKF are introduced to remove the artificially induced resonance. It is found that short assimilation window lengths not only remove the spurious resonance, but also push the migrating semi-diurnal temperature variation at 50 Pa closer to the estimated "true" tides even in the absence of a radiatively active water ice cloud parameterization. In order to compare the performance of different assimilation window lengths, short-term to long-term forecasts based on the hour 00 and 12 assimilation are evaluated and compared. Results show that during NH summer, it is not the assimilation window length, but the radiatively active water ice cloud that influences the model prediction. A "diurnal bias correction" that includes bias correction fields dependent on the local time is shown to effectively reduce the forecast root mean square differences (RMSD) between forecasts and observations, compensate for the absence of water ice cloud parameterization, and enhance Martian atmosphere prediction. The implications of these results for data assimilation in the Earth's atmosphere are also discussed

Financial intermediation and economic performance in Zimbabwe

Financial literature is replete with theoretical and empirical evidence suggesting financial development has a causal effect on economic growth. Yet there is no consensus on the finance-growth nexus. The direction of causality is still controversial In fact, classical economists argue that financial factors are neutral and hence cannot have real effects. Critics argue the traditional methods of identifying long run economic relationships fail to address the methodological conflict between equilibrium implied by theory and the disequilibria in the data. The rise of new representation techniques such as the General Methods of Moments (GMM) and vector autoregression [VAR] brought with them empirical flexibility, which facilitates the re-examination of several theories. VAR characterization permits the economic system to determine the behavior of macroeconomic variables simultaneously. The endogenous growth theoretical literature gives credibility to system-wide V AR financial models. This research is both critical (in its search for a common framework to inform debate on Zimbabwe) and positive (to the extent it undertakes an empirical investigation.) Empirically, the study examines the nature and intensity of links between financial intermediation and economic performance in a small developing economy. A Vector Autoregressive [VAR] framework is applied to model and estimate the temporal and dynamic relationships between financial aggregates and economic activity. Cointegration among the variables is examined to determine the degree of heterogeneity and coevolution. The general impulse response function [GIRF] and variance decomposition [VDC] analytical techniques are applied to throw light on the speed and direction of the causal links and the persistence of shocks over time. Branches of financial theory, e.g. agency risk, corporate governance and information asymmetry have taught us economic activity does not take place in a vacuum or perfect market. To put this research into perspective, the study critically examines the evolution of Zimbabwean institutional structures in search of a new conceptual framework with potential to inform debate. The works of Levine (1997, 1998) LaPorta, Lopez-de-Silanes, Shleifer and Vishny (1997, 1998, 2000), Beck, Levine and Loayza (2000), Kane (1981, 1983, 2000) Jensen and Meckling (1976) and Stiglitz (1989) give considerable prominence to governance and institutional design. Allen and Gale(1994, p10) emphasized that institutional settings underlie the process of financial innovation. In fact, Schumpeter (1954, p12) exalts history, statistics and theory as the three pillars of economic analysis. Stiglitz (1989, p199) agrees that particular localized historical events could have permanent effects. More recently, Beck, Demirgüç-Kunt and Levine (2001) summarized the theory and provided an empirical examination of the links between laws, politics and finance

Bowdoin Orient v.125, no.1-25 (1994-1995)

https://digitalcommons.bowdoin.edu/bowdoinorient-1990s/1006/thumbnail.jp

The intermestic development circle and the usefulness of a civil society concept in non-western contexts: the case of Bangladesh

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