ARKATKAR, ISHA. ALACRI2TY: Lossless Data Compression for Analytics-driven Query Processing. (Under the direction of Nagiza F. Samatova.) Analysis of scientific simulations is highly data-intensive and is becoming an increasingly important challenge. Peta-scale data sets require us to look for alternative ways of performing query-driven analyses. This thesis is an attempt in the direction of que...

Compression boosting (Ferragina & Manzini, SODA 2004) is a new technique to enhance zeroth order entropy compressors’ performance to k-th order entropy. It works by constructing the BurrowsWheeler transform of the input text, finding optimal partitioning of the transform, and then compressing each piece using an arbitrary zeroth order compressor. The optimal partitioning has the property that t...

OBJECTIVES To evaluate and compare nonoperative treatment methods for traumatic thoracic and lumbar compression fractures and burst fractures. DESIGN Prospective randomized controlled trial with long-term follow-up. SETTING Two general hospitals in the Netherlands. PATIENTS/PARTICIPANTS Patients with a traumatic thoracic or lumbar spine fracture, without neurologic damage, with less than ...

Efficient access to the inverted index data structure is a key aspect for a search engine to achieve fast response times to users’ queries. While the performance of an information retrieval (IR) system can be enhanced through the compression of its posting lists, there is little recent work in the literature that thoroughly compares and analyses the performance of modern integer compression sch...

Determination of the suction compression index, Ch, is necessary for predicting expansive soil heave based on soil suction. The CLOD Test is a convenient laboratory procedure for determining Ch, however it is not widely used. Rather, engineers often rely upon empirical correlations to find Ch. A laboratory investigation was conducted to verify previously established empirical relationships. The...

Databases can store large amounts of data. each stored entity is a complex structure, called a record. Records are indexed based on the values of certain fields. A techniques for indexing data is provide.a method for compressed an index to obtain a compressed index that is easily stored and transmitted. The invention also provides for the decompression of such a compressed index. The main aim o...

BACKGROUND The surgical treatment of occipital headaches focuses on the greater, lesser, and third occipital nerves. The lesser occipital nerve (LON) is usually transected with relatively limited available information regarding the compression topography thereof and how such knowledge may impact surgical treatment. METHODS Eight fresh frozen cadavers were dissected focusing on the LON in rela...

Abstract. The recent process of digitalizing archives has increased the importance of choosing the best compression method and evaluating the quality of the compressed materials. Our paper focuses on monochrome portrait photographs. We suggest using an image quality index partly based on Human Visual System. We think that, despite its simplicity, it equals with Mean Subjective Rank. In addition...

The recent process of digitalizing archives has increased the importance of choosing the best compression method and evaluating the quality of the compressed materials. Our paper focuses on monochrome photographs. We suggest a new image quality index partly based on Human Visual System. We think that, despite its simplicity, it is equal to Mean Subjective Rank. In addition, we intend to ascerta...

Document identifier assignment is a technique for inverted file index compression, by reducing d-gap value of posting lists. It was approached by either TSP or clustering methods in existing study. However, there is no proper formulation for this problem and the existing approaches has no theory guarantee to be good approximations. In this paper, we first formulate document identifier assignmen...