620 research outputs found
Performance comparison of point and spatial access methods
In the past few years a large number of multidimensional point access methods, also called
multiattribute index structures, has been suggested, all of them claiming good performance. Since no
performance comparison of these structures under arbitrary (strongly correlated nonuniform, short
"ugly") data distributions and under various types of queries has been performed, database
researchers and designers were hesitant to use any of these new point access methods. As shown in
a recent paper, such point access methods are not only important in traditional database applications.
In new applications such as CAD/CIM and geographic or environmental information systems, access
methods for spatial objects are needed. As recently shown such access methods are based on point
access methods in terms of functionality and performance. Our performance comparison naturally
consists of two parts. In part I we w i l l compare multidimensional point access methods, whereas in
part I I spatial access methods for rectangles will be compared. In part I we present a survey and
classification of existing point access methods. Then we carefully select the following four methods
for implementation and performance comparison under seven different data files (distributions) and
various types of queries: the 2-level grid file, the BANG file, the hB-tree and a new scheme, called
the BUDDY hash tree. We were surprised to see one method to be the clear winner which was the
BUDDY hash tree. It exhibits an at least 20 % better average performance than its competitors and is
robust under ugly data and queries. In part I I we compare spatial access methods for rectangles.
After presenting a survey and classification of existing spatial access methods we carefully selected
the following four methods for implementation and performance comparison under six different data
files (distributions) and various types of queries: the R-tree, the BANG file, PLOP hashing and the
BUDDY hash tree. The result presented two winners: the BANG file and the BUDDY hash tree.
This comparison is a first step towards a standardized testbed or benchmark. We offer our data and
query files to each designer of a new point or spatial access method such that he can run his
implementation in our testbed
How Do You Like Me in This: User Embodiment Preferences for Companion Agents
We investigate the relationship between the embodiment of an artificial companion and user perception and interaction with it. In a Wizard of Oz study, 42 users interacted with one of two embodiments: a physical robot or a virtual agent on a screen through a role-play of secretarial tasks in an office, with the companion providing essential assistance. Findings showed that participants in both condition groups when given the choice would prefer to interact with the robot companion, mainly for its greater physical or social presence. Subjects also found the robot less annoying and talked to it more naturally. However, this preference for the robotic embodiment is not reflected in the usersâ actual rating of the companion or their interaction with it. We reflect on this contradiction and conclude that in a task-based context a user focuses much more on a companionâs behaviour than its embodiment. This underlines the feasibility of our efforts in creating companions that migrate between embodiments while maintaining a consistent identity from the userâs point of view
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Tit-Âââfor-ÂââTat: Effects of Feedback and Speaker Reliability on ListenerComprehension Effort
Miscommunication is often seen as a detrimental aspectof human communication. However, miscommunicationcan differ in cause as well as severity. What distinguishesa miscommunication where conversation partnerscontinue to put forth the effort from miscommunicationwhere conversation partners simply give up? In this eye-Âââtracking study, participants heard globally ambiguousstatements that were either a result of an experimentalerror or speaker underspecification; participants eitherreceived positive or negative feedback on theseambiguous trials. We found that negative feedback,paired with the reliability of the message, will impact theamount of processing effort a comprehender putsforthâspecifically, listeners were less forgiving of errorswhen they were penalized and when speakersâinstructions lacked effort. This suggests that languageusers weigh conversational contexts and outcomes aswell as linguistic content during communication
Feed-forward Torque Control of Interior Permanent Magnet Brushless AC Drive for Traction Applications
This paper presents a feed-forward torque control
(FTC) technique for interior permanent magnet (IPM) brushless
AC (BLAC) drives in traction applications. It is shown that by
adopting the Newton-Raphson iterative method for solving the
proposed high-order nonlinear relationship between the torque
demand, flux-linkage and desirable dq-axis currents, FTC with
due account of nonlinear machine parameters can be achieved
for IPM BLAC drives. It is also proven that the comparison
between the reference voltage magnitudes under maximum
torque per ampere (MTPA) and field-weakening (FW)
operations together with online base speed determination can be
utilized for FW operation activation to achieve full exploitation
of the available DC-link voltage during the transition between
the constant torque and FW operation regions. Since both the dqaxis
current references and the base speed for FW operation
activation are computed online, the proposed FTC technique
provides flexibility for online parameter update or estimation
and is able to cope with wide DC-link voltage variation. The
proposed FTC strategy is experimentally validated by
measurements on a 10kW wide constant power speed range
(CPSR) IPM BLAC machine drive
Predicting the Next Best View for 3D Mesh Refinement
3D reconstruction is a core task in many applications such as robot
navigation or sites inspections. Finding the best poses to capture part of the
scene is one of the most challenging topic that goes under the name of Next
Best View. Recently, many volumetric methods have been proposed; they choose
the Next Best View by reasoning over a 3D voxelized space and by finding which
pose minimizes the uncertainty decoded into the voxels. Such methods are
effective, but they do not scale well since the underlaying representation
requires a huge amount of memory. In this paper we propose a novel mesh-based
approach which focuses on the worst reconstructed region of the environment
mesh. We define a photo-consistent index to evaluate the 3D mesh accuracy, and
an energy function over the worst regions of the mesh which takes into account
the mutual parallax with respect to the previous cameras, the angle of
incidence of the viewing ray to the surface and the visibility of the region.
We test our approach over a well known dataset and achieve state-of-the-art
results.Comment: 13 pages, 5 figures, to be published in IAS-1
Protein kinase Ymr291w/Tda1 is essential for glucose signaling in Saccharomyces cerevisiae on the level of hexokinase isoenzyme ScHxk2 phosphorylation
The enzyme ScHxk2 of Saccharomyces cerevisiae is a dual-function hexokinase that besides its catalytic role in glycolysis is involved in the transcriptional regulation of glucose-repressible genes. Relief from glucose repression is accompanied by the phosphorylation of the nuclear fraction of ScHxk2 at serine 15 and the translocation of the phosphoenzyme into the cytosol. Different studies suggest different serine/threonine protein kinases, Ymr291w/Tda1 or Snf1, to accomplish ScHxk2-S15 phosphorylation. The current paper provides evidence that Ymr291w/Tda1 is essential for that modification while protein kinases Ydr477w/Snf1, Ynl307c/Mck1, Yfr014c/Cmk1 and Ykl126w/Ypk1, which co-purified during Ymr291w/Tda1 tandem affinity purification, as well as protein kinases PKA and PKB homolog Sch9 are dispensable. Taking into account the detection of a significantly higher amount of the Ymr291w/Tda1 protein in cells grown in low-glucose media as compared to a high-glucose environment, Ymr291w/Tda1 is likely to contribute to glucose signaling in Saccharomyces cerevisiae on the level of ScHxk2-S15 phosphorylation in a situation of limited external glucose availability. The evolutionary conservation of amino acid residue serine 15 in yeast hexokinases and its phosphorylation is illustrated by the finding that YMR291W/TDA1 of Saccharomyces cerevisiae and the homologous KLLA0A09713 gene of Kluyveromyces lactis allow for cross-complementation of the respective protein kinase single-gene deletion strains
Personhood, consciousness, and god : how to be a proper pantheist
© Springer Nature B.V. 2018In this paper I develop a theory of personhood which leaves open the possibility of construing the universe as a person. If successful, it removes one bar to endorsing pantheism. I do this by examining a rising school of thought on personhood, on which persons, or selves, are understood as identical to episodes of consciousness. Through a critique of this experiential approach to personhood, I develop a theory of self as constituted of qualitative mental contents, but where these contents are also capable of unconscious existence. On this theory, though we can be conscious of our selves, consciousness turns out to be inessential to personhood. This move, I then argue, provides resources for responding to the pantheistâs problem of Godâs person.Peer reviewedFinal Accepted Versio
Incidental MALT Type Lymphoma Exhibiting Prominent Plasma Cell Differentiation Associated with Hashimotoâs Thyroiditis. A Two Case Report
We present here two cases of incidental extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma) showing prominent plasma cell differentiation associated with Hashimotoâs thyroiditis (HT). Histological examination demonstrated that both lesions exhibited HT including lymphoplasmacytic infiltration with the formation of germinal centers, destruction of the normal thyroid follicular architecture, HĂŒrthle cell changes, and squamous metaplasia. The dominant tumor nodules of both cases contained large, well-circumscribed but unencapsulated aggregation of mature plasma cells and scattered centrocyte-like cells (CCL-cells). Both lesions contained a few lymphoepithelial lesions. Moreover, immunohistochemical study demonstrated that plasma cells and CCL-cells of these two lesions contained monotypic intracytoplasmic kappa light chain. Other small B-cell lymphomas, plasmacytoma and plasmablastic lymphoma were excluded using stains for CD5, CD10, CD23, CD43, CD56. Cyclin D1, human herpes virus type-8
Transrectal Prostate Biopsy and Fiducial Marker Placement in a Standart 1.5T Magnetic Resonance Imaging Scanner
Cataloged from PDF version of article.Purpose: We investigated the accuracy and feasibility of a system that provides transrectal needle access to the prostate concurrent with 1.5 Tesla MRI which previously has not been possible.
Materials and Methods: In 5 patients with previously diagnosed prostate cancer, MRI guided intraprostatic placement of gold fiducial markers (4 procedures) and/or prostate biopsy (3 procedures) was performed using local anesthesia.
Results: Mean procedure duration was 76 minutes and all patients tolerated the intervention well. Procedure related adverse events included self-limited hematuria and hematochezia following 3 of 8 procedures (all resolved in less than 1 week). Mean needle placement accuracy was 1.9 mm for the fiducial marker placement studies and 1.8 mm for the biopsy procedures. Mean fiducial marker placement accuracy was 4.8 mm and the mean fiducial marker placement accuracy transverse to the needle direction was 2.6 mm. All patients who underwent the procedure were able to complete their course of radiotherapy without delay or complication.
Conclusions: While studies of clinical usefulness are warranted, transrectal 1.5 T MRI guided prostate biopsy and fiducial marker placement is feasible using this system, providing new opportunities for image guided diagnostic and therapeutic prostate interventions
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