Expert Systems as Overlapping Logical Theories

Abstract We discuss the model-theoretic characterization of the components of logic-based expert systems which employ pure meta-level inference regimes. The roles of the basic components of such systems in the underlying fust order theories are specified. This includes the domain specific rules, meta-level inference engine, and intrinsic interpreter. Fragments of an actual expert system are used to motivate and illustrate the analysis

An extension of Ukkonen’s enhanced dynamic programming ASM algorithm

We describe an improvement on Ukkonen's Enhanced Dynamic Programming (EHD) approximate string-matching algorithm for unit-penalty four-edit comparisons. The new algorithm has an asymptotic complexity similar to that of Ukkonen's but is significantly faster due to a decrease in the number of array cell calculations. A 42% speedup was achieved in an application involving name comparisons. Even greater improvements are possible when comparing longer and more dissimilar strings. Although the speed of the algorithm under consideration is comparable to other fast ASM algorithms, it has greater effectiveness in text-processing applications because it supports all four basic Damerau-type editing operations

Publishing Wikipedia usage data with strong privacy guarantees

For almost 20 years, the Wikimedia Foundation has been publishing statistics about how many people visited each Wikipedia page on each day. This data helps Wikipedia editors determine where to focus their efforts to improve the online encyclopedia, and enables academic research. In June 2023, the Wikimedia Foundation, helped by Tumult Labs, addressed a long-standing request from Wikipedia editors and academic researchers: it started publishing these statistics with finer granularity, including the country of origin in the daily counts of page views. This new data publication uses differential privacy to provide robust guarantees to people browsing or editing Wikipedia. This paper describes this data publication: its goals, the process followed from its inception to its deployment, the algorithms used to produce the data, and the outcomes of the data release.Comment: 11 pages, 10 figures, Theory and Practice of Differential Privacy (TPDP) 202

Simultaneous storage of medical images in the spatial and frequency domain: A comparative study

BACKGROUND: Digital watermarking is a technique of hiding specific identification data for copyright authentication. This technique is adapted here for interleaving patient information with medical images, to reduce storage and transmission overheads. METHODS: The patient information is encrypted before interleaving with images to ensure greater security. The bio-signals are compressed and subsequently interleaved with the image. This interleaving is carried out in the spatial domain and Frequency domain. The performance of interleaving in the spatial, Discrete Fourier Transform (DFT), Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT) coefficients is studied. Differential pulse code modulation (DPCM) is employed for data compression as well as encryption and results are tabulated for a specific example. RESULTS: It can be seen from results, the process does not affect the picture quality. This is attributed to the fact that the change in LSB of a pixel changes its brightness by 1 part in 256. Spatial and DFT domain interleaving gave very less %NRMSE as compared to DCT and DWT domain. CONCLUSION: The Results show that spatial domain the interleaving, the %NRMSE was less than 0.25% for 8-bit encoded pixel intensity. Among the frequency domain interleaving methods, DFT was found to be very efficient

Through the PRISM Darkly

The Foreign Intelligence Surveillance Court has an approval rate of 99.93 percent of all surveillance requests. While this might not meet the strict definition of a kangaroo court, it seems to fall within the marsupial family

The SCDOR Hack: Great Security Theater in Five Stages

The South Carolina governor\u27s response to the SCDOR hack represents a textbook application of Elisabeth Kübler-Ross\u27s five stages of grief to cybersecurity

Computing Technology and Survivable Journalism

Ironically, the very technology that the media pundits suggest might get journalism out of the hole might actually be making the hole deeper

Toxic Cookies

The W3C has shown what can happen when bright, well-intentioned people become policy czars