How Advances in Search Combine Databases, Sentence Diagramming, and "Just the Facts"

Among the most studied subfields of natural language processing (NLP) are information retrieval (IR, aka search) and information extraction (IE). Yet, even though researchers have wanted to combine IR and IE for nearly a decade, we are only now starting to see commercial applications that put the notion into practice. The search market remains dominated by traditional IR technologies, as evidenced by the likes of Google, Yahoo, and Verity. (Granted, Google's page-rank algorithm departs from traditional IR algorithms by including link data, but the underlying index of terms is conventional.) Two forces are driving the need for advanced search technologies: (a) users are more knowledgeable and are demanding greater search engine precision; and (b) vendors must create new search products, particularly enterprise search applications. This issue's theme articles represent several of these advancements. In this article, the author detail how IE-in particular action-oriented event extraction-enables new search functionality     

Growth and characterization of GaAs films deposited on Ge/Si composite substrates by metalorganic chemical vapor deposition

We report the results of studies which have been made on heteroepitaxial layers of GaAs and AlGaAs grown by metalorganic chemical vapor deposition on composite substrates that consist of four different types of heteroepitaxial layered structures of Ge and Ge-Si grown by molecular beam epitaxy on (100)-oriented Si substrates. It is found that of the four structures studied, the preferred composite substrate is a single layer of Ge ∼1 μm thick grown directly on a Si buffer layer. The double-crystal X-ray rocking curves of 2 μm thick GaAs films grown on such substrates have FWHM values as small as 168 arc sec. Transmission electron micrographs of these Ge/Si composite substrates has shown that the number of dislocations in the Ge heteroepitaxial layer can be greatly reduced by an anneal at about 750° C for 30 min which is simultaneously carried out during the growth of the GaAs layer. The quality of the GaAs layers grown on these composite substrates can be greatly improved by the use of a five-period GaAs-GaAsP strained-layer superlattice (SLS). Using the results of these studies, low-threshold optically pumped AlGaAs-GaAs DH laser structures have been grown by MOCVD on MBE Ge/Si composite substrates.     

Theory of reflectivity of an asymmetric mirror

By using the concept of transfer matrices and Bloch waves, we have derived a set of equations that provide insight into the operation of asymmetric Bragg reflectors that have been demonstrated to be useful in achieving high reflectivities in strained-material systems. These equations will be useful in the design of asymmetric mirrors and can be used to compare the trade-offs between the conventional, symmetric (quarter-wavelength), and asymmetric mirrors.     

Autonomous clustering using rough set theory

This paper proposes a clustering technique that minimizes the need for subjective human intervention and is based on elements of rough set theory （RST）. The proposed algorithm is unified in its approach to clustering and makes use of both local and global data properties to obtain clustering solutions. It handles single-type and mixed attribute data sets with ease. The results from three data sets of single and mixed attribute types are used to illustrate the technique and establish its efficiency.     

Effects of ascorbic acid concentration on the tissue engineering of the temporomandibular joint disc

The temporomandibular joint (TMJ) disc is a specialized fibrocartilaginous tissue. When the disc becomes an obstacle and becomes damaged, surgeons have no choice but to perform a discectomy. Tissue engineering may provide a novel treatment modality for TMJ disorder patients who undergo discectomy. No studies have been conducted on the most favourable media for TMJ disc cells. The objective of the current study was to examine the effects on biochemical and biomechanical properties of varying ascorbic acid concentrations (0, 25, or 50 microg/ml) on TMJ disc cells seeded on non-woven PGA scaffolds. The ascorbic acid concentration of the 25 microg/ml group resulted in more effective cell seeding of the scaffolds, with 1.53 million cells per construct, by comparison with the 0 and 50 microg/ml groups which had 1.20 million and 1.32 million cells per scaffold respectively. At week 4, the 25 microg/ml group had a higher collagen content than the 0 microg/ml group, with 30.4 +/- 2.7 and 24.9 +/- 3.3 microg of collagen per construct respectively. The 25 microg/ml group had a higher aggregate modulus than the 50 microg/ml group, with values of 6.1 +/- 1.3 and 4.0 +/- 0.9 kPa respectively at week 4. The results of this study indicate that the use of 25 microg/ml of ascorbic acid in culture media is effective for the tissue engineering of the TMJ disc, significantly outperforming media without or with 50 microg/ml of ascorbic acid.     

Psychosocial and health consequences of adolescent depression in Black and White young adult women.

Depression in adolescent girls may result in negative consequences in young adulthood. The Center for Epidemiologic Studies Depression Scale (CES-D) was administered to 1,727 Black and White girls ages 16 to 18 years who participated in the National Heart, Lung, and Blood Institute's Growth and Health Study. Three years later, women in the depressed groups were more likely to be current smokers, had attained a lower level of education, and reported lower self-worth relative to the nondepressed group. Body dissatisfaction, eating concerns, and loneliness were greater in the depressed groups. Relative to Black women, White women who were moderately depressed during adolescence reported more health care services utilization in young adulthood. Prevention efforts for depressed adolescents should be broadly focused to improve young adult outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparing Five and Lower-Dimensional Grain Boundary Character and Energy Distributions in Copper: Experiment and Molecular Statics Simulation

Metallurgical and Materials Transactions A - The misorientation of 515 grain boundaries has been determined using electron backscatter diffraction data from an 18 μm thick copper foil with...     

Evaluation of Four Permeable Pavement Sites in Eastern North Carolina for Runoff Reduction and Water Quality Impacts

Four permeable pavement applications in North Carolina’s Coastal Plain were constructed and monitored to determine their effectiveness of reducing runoff quantity and improving water quality. Sites were either constructed of permeable interlocking concrete pavers (2), porous concrete (1), or concrete grid pavers (1). One site of each pavement type was monitored for runoff reduction for periods ranging from 10 to 26 months. Measured runoff depths from rainfall events over 50?mm were used to determine permeable pavement equivalent curve numbers for the sites, which ranged from 45 to 85. Only the two permeable interlocking concrete pavement (PICP) sites were monitored for water quality. Runoff and exfiltrate samples were intended to be collected, in addition to runoff monitoring, from the Swansboro PICP site. However, no runoff was produced during this study from the Swansboro PICP site for rainfall events up to 88?mm. From exfiltrate concentrations, nutrient retention was estimated to be 3.4 and 0.4?kg/ha/year for total nitrogen and total phosphorus, respectively. For the Goldsboro PICP site, water quality of asphalt runoff and PICP exfiltrate were compared. Analysis of water quality samples from the second site determined that concentrations of total Kjeldahl nitrogen, ammonia, total phosphorus, and zinc were significantly (p ? 0.05) lower in permeable pavement exfiltrate than asphalt runoff.     

Scheduling operations on parallel machine tools

We introduce unique scheduling problems that arise for multiple spindle machine tools. The ability of these machines to perform simultaneous operations on more than one part creates constraints that are not found in the traditional scheduling literature. Two types of solution procedures are introduced for these problems. The first uses priority dispatching rules and a delay factor concept, while the second uses a genetic algorithm with a random keys encoding. The effectiveness of these methods is demonstrated on test problems with comparisons to lower bounds