405 research outputs found
Tractability of Theory Patching
In this paper we consider the problem of `theory patching', in which we are
given a domain theory, some of whose components are indicated to be possibly
flawed, and a set of labeled training examples for the domain concept. The
theory patching problem is to revise only the indicated components of the
theory, such that the resulting theory correctly classifies all the training
examples. Theory patching is thus a type of theory revision in which revisions
are made to individual components of the theory. Our concern in this paper is
to determine for which classes of logical domain theories the theory patching
problem is tractable. We consider both propositional and first-order domain
theories, and show that the theory patching problem is equivalent to that of
determining what information contained in a theory is `stable' regardless of
what revisions might be performed to the theory. We show that determining
stability is tractable if the input theory satisfies two conditions: that
revisions to each theory component have monotonic effects on the classification
of examples, and that theory components act independently in the classification
of examples in the theory. We also show how the concepts introduced can be used
to determine the soundness and completeness of particular theory patching
algorithms.Comment: See http://www.jair.org/ for any accompanying file
Committee-Based Sample Selection for Probabilistic Classifiers
In many real-world learning tasks, it is expensive to acquire a sufficient
number of labeled examples for training. This paper investigates methods for
reducing annotation cost by `sample selection'. In this approach, during
training the learning program examines many unlabeled examples and selects for
labeling only those that are most informative at each stage. This avoids
redundantly labeling examples that contribute little new information. Our work
follows on previous research on Query By Committee, extending the
committee-based paradigm to the context of probabilistic classification. We
describe a family of empirical methods for committee-based sample selection in
probabilistic classification models, which evaluate the informativeness of an
example by measuring the degree of disagreement between several model variants.
These variants (the committee) are drawn randomly from a probability
distribution conditioned by the training set labeled so far. The method was
applied to the real-world natural language processing task of stochastic
part-of-speech tagging. We find that all variants of the method achieve a
significant reduction in annotation cost, although their computational
efficiency differs. In particular, the simplest variant, a two member committee
with no parameters to tune, gives excellent results. We also show that sample
selection yields a significant reduction in the size of the model used by the
tagger
The Roberta Mitchell Lecture: Structuring Responsibility in Securitization Transactions
In this Lecture, Professor Schwarcz examines how complex securitization transactions may have created a “protection gap,” the conundrum that transaction parties may be unable to purchase or might not want to pay the price for full protection. As a result, they sometimes choose or are forced to assume the good faith of the other parties to the transaction and the consistency and completeness of protections provided in the transaction documents
Subdivisions for Biblical Studies, Theology, and Ministry: Making Search Terms Do the Work
Navigating the immense quantity of information available today is a daunting task for most people. As librarians well know, resources available freely from the Internet are easy to search and access, however, not all information needs are satisfied by a Google search.
This book focuses on subdivisions that are of explicit value for researchers and librarians in the areas of theology, biblical studies, and pastoral ministry from the perspective of someone studying for Christian ministry or actively involved in ministry.
About the Author: Leslie A Engelson
Leslie Engelson is currently assistant professor and Metadata Librarian at Murray State University in Murray, Kentucky. Prior to this position, she was the Technical Services Librarian at Northwest University in Kirkland, Washington, where she also served as library liaison to NU\u27s College of Ministry. Leslie is keenly interested in finding ways to help people access information, whether that\u27s through talking with faculty about open access, creating quality cataloging records, or encouraging the use of controlled vocabulary in information literacy instruction. Additionally, Leslie teaches a graduate course in organizing and managing library collections in the Library Media Program at MSU.
(Description from publisher)https://digitalcommons.murraystate.edu/libraries_book/1000/thumbnail.jp
Use of a reflective ultraviolet imaging system (RUVIS) on two-dimensional dust impressions created with footwear on multiple substrates
Footwear impression evidence in dust is often difficult to locate in ambient light and is a fragile medium that both collection and enhancement techniques can destroy or distort. The collection of footwear impression evidence always begins with non-destructive photographic techniques; however, current methods are limited to oblique lighting of the impression followed by an attempt to photograph in situ12,15,17. For the vast majority of footwear impressions, an interactive collection method, and thus a potentially destructive procedure, is subsequently carried out to gather the evidence18. Therefore, alternative non-destructive means for the preservation and enhancement of footwear impressions in dust merits further attention.
Previous research performed with reflected ultraviolet (UV) photography and reflected ultraviolet imaging systems (RUVIS) has shown that there are additional non-destructive methodologies that can be applied to the search for and documentation of footwear impressions in dust34,36,37. Unfortunately, these prior studies did not include robust comparisons to traditional oblique white light, instead choosing to focus on different UV wavelengths. This study, however, seeks to evaluate the use of a RUVIS device paired with a 254 nanometer (nm) UV light source to locate 2-D footwear impressions in dust on multiple substrates against standard oblique white light techniques and assess the visibility of the impression and amount of background interference present. The optimal angle of incident UV light for each substrate was also investigated. Finally, this study applied an image enhancement technique in order to evaluate its usefulness when looking at the visibility of a footwear impression and the amount of background interference present for enhanced white light and RUVIS pictures of footwear impressions in dust.
A collection of eight different substrate types was gathered for investigation, including vinyl composition tile (VCT), ceramic tile, marble tile, magazine paper, steel sheet metal, vinyl flooring, wood flooring, and carpet. Heel impressions were applied to the various substrates utilizing vacuum collected dust and normal walking pressure. Each substrate was then explored and photographed in ambient fluorescent light, oblique white light at 0, 15, 30, and 0 with the light source below the surface plane of the substrate, and 254 nm UV light at 0, 15, 30, 45, 60, 75, 90 and 0 with the light source below the surface plane of the substrate. All pictures were evaluated for clarity and visible detail of the footwear impression and the amount of background interference present, selecting for the best images within a lighting condition group. Additional intra- and intergroup comparisons were carried out to explore differences created by the various lighting conditions. Enhanced images were then created with the best scored pictures and evaluated for additional modifications in impression visibility and background interference.
Photographs of footwear impressions in dust illuminated with ambient fluorescent light proved to be the most difficult conditions under which a footwear impression could be visualized. However, both oblique white light and 254 nm UV light lighting conditions showed improvements in either visualization or background dropout, or both, over ambient light conditions. An assessment of the white light and 254 nm UV light RUVIS images also demonstrated that the best angles for the light source for all substrates were oblique 0 and oblique 0 below the surface plane of the substrate lighting. It was found that white light photographs generally provided higher visibility ratings, while RUVIS 254 nm UV light photographs provided better grades for reducing background interference. Enhanced images of white light conditions provided generally poorer quality and quantity of details, while enhanced RUVIS images seemed to improve upon these areas.
The use of a RUVIS to capture photographs of footwear impression evidence in dust was found to be a successful secondary non-destructive technique that can be paired with traditional oblique white light procedures. Additionally, the use of below the surface plane of the substrate lighting techniques were found to improve either visibility or background dropout, or both, over standard 0 oblique lighting, depending on the light source, and should be employed, when applicable. Finally, further investigation into digital photo-editing enhancement techniques for footwear impression evidence in dust is needed
The Biblical Value of Pi in Light of Traditional Judaism
There are numerous attempts at a solution to the puzzle as to why the Biblical value of pi, as demonstrated by the measurements of King Solomon\u27s pool, is exactly 3 and not a better approximation. This article shows that virtually all such published solutions are deficient because volume-based factors are ignored. Issues respecting the volume of this pool are explained, and some possible solutions of the puzzle are presented
Three Channel Polarimetric Based Data Deconvolution
A three channel polarimetric deconvolution algorithm was developed to mitigate the degrading effects of atmospheric turbulence in astronomical imagery. Tests were executed using both simulation and laboratory data. The resulting efficacy of the three channel algorithm was compared to a recently developed two channel approach under identical conditions ensuring a fair comparison amongst both algorithms. Two types of simulations were performed. The first was a binary star simulation to compare resulting resolutions between the three and two channel algorithms. The second simulation measured how effective both algorithms could deconvolve a blurred satellite image. The simulation environment assumed the key parameters of Fried\u27s Seeing parameter, , and telescope lens diameters of and . The simulation results showed that the three channel algorithm always reconstructed the true image as good as or better than the two channel approach, while the total squared error was always significantly better for the three channel algorithm. The next step is comparing the two algorithms in the laboratory environment. However, the laboratory imagery was not actually blurred by atmospheric turbulence, but instead camera defocusing was used to simulate the blurring that would be caused by atmospheric turbulence. The results show that the three channel significantly outperforms the two channel in a visual reconstruction of the true image
Telling Your Story: Articulating Your Value as a Technical Services Librarians
If you can translate your skills and achievements so others see their value and impact, everyone wins.
Whether justifying the need to fill an open position, writing a tenure or promotion narrative, or even carrying on a conversation with a colleague, librarians who work in Technical Services are often challenged to articulate what they do and the value it brings to the institution they serve. In this webinar we will discuss: The challenge of defining value in the context of technical services Assessment measures that determine the impact of technical services “products” on users Connecting the impact of technical services to the mission of the institution Developing a 30-second elevator speech to explain the value of technical services to those outside the librar
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