Event Normalization Through Dynamic Log Format Detection

The analytical and monitoring capabilities of central event repositories, such as log servers and intrusion detection systems, are limited by the amount of structured information extracted from the events they receive. Diverse networks and applications log their events in many different formats, and this makes it difficult to identify the type of logs being received by the central repository. The way events are logged by IT systems is problematic for developers of host-based intrusiondetection systems(specifically, host-based systems), developers of security-information systems, and developers of eventmanagement systems. These problems preclude the development of more accurate, intrusive security solutions that obtain results from data included in the logs being processed. We propose a new method for dynamically normalizing events into a unified super- event that is loosely based on the Common Event Expression standard developed by Mitre Corporation.We explain how our solution can normalize seemingly unrelated events into a single, unified format.     

Asymmetric slab and strip-loaded integrated optic devices for the measurement of large electric fields

Two modifications of the integrated optic Mach-Zehnder interferometer device are proposed which could be used to measure large electric fields, for example, in high voltage lines in utility substations. These new devices consist of an asymmetric slab and a strip-loaded diffused waveguide. They would merely be immersed in the field to be measured. Interrogation would be by optical fiber. The theory of operation of these devices is developed and examples are worked using the optical constants of possible materials.     

Assessment of parathyroid gland function: predictive value of a nomogram

Recent developments in measurement of intact parathormone (PTH) has enabled to generate a nomogram for parathyroid function. Blood levels of PTH can thus be interpreted in relation to calcemia. Intact PTH and calcium were assayed in blood from 99 healthy subjects studied under fasting conditions; 26 subjects were also studied during hyper- and hypocalcemia, induced by calcium and EDTA infusions, respectively. Serum levels of intact PTH which had been obtained in 99 patients were then analysed retrospectively by comparison with the nomogram. Patients whose intact PTH levels lie above the normal zone of the nomogram produce too much PTH relative to the blood calcium level (hyperparathyroidism); those falling under the normal zone produce too little (hypoparathyroidism).     

Inhomogeneous exciton broadening and mean free path in In1-xGaxAsyP1-y-InP heterostructures

Absorption and electroabsorption spectra are investigated at low temperature to derive broadening parameters of excitonic absorption edges in the alloy crystals. A strong increase of the inhomogeneous linewidth of excitons is observed for quaternary material which exceeds significantly the width expected from compositional fluctuations. The linewidth decreases again for phosphorous rich samples. Franz-Keldysh oscillations above the absorption edge contain information on the coherence length of band states. They show a corresponding decrease of the mean free path from 150 nm for ternary material to 70 nm for quaternary material     

A direct digital frequency synthesizer with fourth-order phase domain /spl Delta//spl Sigma/ noise shaper and 12-bit current-steering DAC

This paper presents a direct digital frequency synthesizer (DDFS) with a 16-bit accumulator, a fourth-order phase domain single-stage /spl Delta//spl Sigma/ interpolator, and a 300-MS/s 12-bit current-steering DAC based on the Q/sup 2/ Random Walk switching scheme. The /spl Delta//spl Sigma/ interpolator is used to reduce the phase truncation error and the ROM size. The implemented fourth-order single-stage /spl Delta//spl Sigma/ noise shaper reduces the effective phase bits by four and reduces the ROM size by 16 times. The DDFS prototype is fabricated in a 0.35-/spl mu/m CMOS technology with active area of 1.11mm/sup 2/ including a 12-bit DAC. The measured DDFS spurious-free dynamic range (SFDR) is greater than 78 dB using a reduced ROM with 8-bit phase, 12-bit amplitude resolution and a size of 0.09 mm/sup 2/. The total power consumption of the DDFS is 200mW with a 3.3-V power supply.