606 research outputs found
ΠΠ²ΡΠΎΠΌΠ°ΡΠΈΡΠ΅ΡΠΊΠ°Ρ ΠΎΠΏΡΠΈΠΌΠΈΠ·Π°ΡΠΈΡ ΡΠ΅Ρ Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠ»Π΅ΠΊΡΠ° ΠΎΠ±ΠΎΠ³Π°ΡΠ΅Π½ΠΈΡ ΠΆΠ΅Π»Π΅Π·Π½ΡΡ ΡΡΠ΄ ΠΏΠΎ ΡΠΈΠ³Π½Π°Π»Π°ΠΌ ΠΌΠ°Π³Π½ΠΈΡΠ½ΠΎΠΉ ΠΈΠ½Π΄ΡΠΊΡΠΈΠΈ ΡΠ΅ΠΏΠ°ΡΠ°ΡΠΎΡΠ°
Recombinant antibodies can be used to diagnose, treat and prevent disease by exploiting their specific antigen-binding activities. A large number of drugs currently in development are recombinant antibodies and most of these are produced in cultured rodent cells. Although such cells produce authentic functional products, they are expensive, difficult to scale-up and may contain human pathogens. Plants represent a cost-effective, convenient and safe alternative production system and are slowly gaining acceptance. Five plant-derived therapeutic recombinant antibodies (plantibodies) are undergoing clinical evaluation, three of which can be used as prophylactics
Deconvolution Processing for Flaw Signatures
The ultimate resolution of all ultrasonic flaw detection systems is limited by transducer response. Although the system output contains detailed information about the target structure, these details are masked by the system characteristics. Since the output can be described as the convolution of the target response and the impulse response of the system, it should- in principle - be possible to reverse this operation and extract the target response. In practice, it is found that the presence of even relatively small amounts of noise make the deconvolution process impossible. If, however, the flaw detection system has an extremely high output signal-to-noise ratio it is possible to use estimation techniques in the deconvolution process to achieve a good approximation to the actual target response. Results are presented that demonstrate these techniques applied to both simulated and experimental data. Coupling deconvolution processing with feature extraction is shown to yield an order of magnitude increase in range resolution
Stochastic EM methods with variance reduction for penalised PET reconstructions
Expectation-maximisation (EM) is a popular and well-established method for image reconstruction in positron emission tomography (PET) but it often suffers from slow convergence. Ordered subset EM (OSEM) is an effective reconstruction algorithm that provides significant acceleration during initial iterations, but it has been observed to enter a limit cycle. In this work, we investigate two classes of algorithms for accelerating OSEM based on variance reduction for penalised PET reconstructions. The first is a stochastic variance reduced EM algorithm, termed as SVREM, an extension of the classical EM to the stochastic context that combines classical OSEM with variance reduction techniques for gradient descent. The second views OSEM as a preconditioned stochastic gradient ascent, and applies variance reduction techniques, i.e., SAGA and SVRG, to estimate the update direction. We present several numerical experiments to illustrate the efficiency and accuracy of the approaches. The numerical results show that these approaches significantly outperform existing OSEM type methods for penalised PET reconstructions, and hold great potential
A Diagram Is Worth A Dozen Images
Diagrams are common tools for representing complex concepts, relationships
and events, often when it would be difficult to portray the same information
with natural images. Understanding natural images has been extensively studied
in computer vision, while diagram understanding has received little attention.
In this paper, we study the problem of diagram interpretation and reasoning,
the challenging task of identifying the structure of a diagram and the
semantics of its constituents and their relationships. We introduce Diagram
Parse Graphs (DPG) as our representation to model the structure of diagrams. We
define syntactic parsing of diagrams as learning to infer DPGs for diagrams and
study semantic interpretation and reasoning of diagrams in the context of
diagram question answering. We devise an LSTM-based method for syntactic
parsing of diagrams and introduce a DPG-based attention model for diagram
question answering. We compile a new dataset of diagrams with exhaustive
annotations of constituents and relationships for over 5,000 diagrams and
15,000 questions and answers. Our results show the significance of our models
for syntactic parsing and question answering in diagrams using DPGs
Flexible code safety for Win32
Thesis (S.B. and M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1999.Includes bibliographical references (p. 90-93).by Andrew R. Twyman.S.B.and M.Eng
Iterative PET Image Reconstruction using Adaptive Adjustment of Subset Size and Random Subset Sampling
Statistical PET image reconstruction methods are often accelerated by the use of a subset of available projections at each iteration. It is known that many subset algorithms, such as ordered subset expectation maximisation, will not converge to a single solution but to a limit cycle. Reconstruction methods exist to relax the update step sizes of subset algorithms to obtain convergence, however, this introduces additional parameters that may result in extended reconstruction times. Another approach is to gradually decrease the number of subsets to reduce the effect of the limit cycle at later iterations, but the optimal iteration numbers for these reductions may be data dependent. We propose an automatic method to increase subset sizes so a reconstruction can take advantage of the acceleration provided by small subset sizes during early iterations, while at later iterations reducing the effects of the limit cycle behaviour providing estimates closer to the maximum a posteriori solution. At each iteration, two image updates are computed from a common estimate using two disjoint subsets. The divergence of the two update vectors is measured and, if too great, subset sizes are increased in future iterations. We show results for both sinogram and list mode data using various subset selection methodologies
Π‘ΠΎΠ·Π΄Π°Π½ΠΈΠ΅ ΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΠ½ΡΡ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΎΠ½Π½ΡΡ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»ΠΎΠ² Ρ Π½Π΅ΠΏΡΠ΅ΡΡΠ²Π½ΡΠΌ Π°ΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π°ΡΠ°ΠΌΠΈΠ΄Π½ΡΠΌ Π²ΠΎΠ»ΠΎΠΊΠ½ΠΎΠΌ Π΄Π»Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ Π² Π°Π΄Π΄ΠΈΡΠΈΠ²Π½ΡΡ ΡΠ΅Ρ Π½ΠΎΠ»ΠΎΠ³ΠΈΡΡ
Π Π΄Π°Π½Π½ΠΎΠΉ ΡΠ°Π±ΠΎΡΠ΅ ΠΏΡΠΎΠ²Π΅Π΄Π΅Π½ΠΎ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΠ΅ ΡΠΎΠ·Π΄Π°Π½ΠΈΡ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° Π½Π° ΠΏΠΎΠ»ΠΈΠΌΠ΅ΡΠ½ΠΎΠΉ ΠΎΡΠ½ΠΎΠ²Π΅ Ρ Π½Π΅ΠΏΡΠ΅ΡΡΠ²Π½ΡΠΌ Π°ΡΠΌΠΈΡΠΎΠ²Π°Π½ΠΈΠ΅ΠΌ Π°ΡΠ°ΠΌΠΈΠ΄Π½ΠΎΠ³ΠΎ Π²ΠΎΠ»ΠΎΠΊΠ½Π° Π΄Π»Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ Π² Π°Π΄Π΄ΠΈΡΠΈΠ²Π½ΡΡ
ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΡ
. ΠΠΏΠΈΡΠ°Π½Ρ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΠΎΡΠΎΠ±Π΅Π½Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ° ΠΌΠΎΠ΄ΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ Π°ΡΠ°ΠΌΠΈΠ΄Π½ΠΎΠ³ΠΎ Π²ΠΎΠ»ΠΎΠΊΠ½Π°. ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΎ Π²Π»ΠΈΡΠ½ΠΈΠ΅ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π° ΠΌΠΎΠ΄ΠΈΡΠΈΠΊΠ°ΡΠΈΠΈ ΠΏΠΎΠ²Π΅ΡΡ
Π½ΠΎΡΡΠΈ Π½Π° Π°Π΄Π³Π΅Π·ΠΈΠΎΠ½Π½ΡΠ΅ ΡΠ²ΠΎΠΉΡΡΠ²Π° ΠΏΠΎΠ»ΡΡΠ°Π΅ΠΌΠΎΠ³ΠΎ ΠΊΠΎΠΌΠΏΠΎΠ·ΠΈΡΠΈΠΎΠ½Π½ΠΎΠ³ΠΎ ΠΌΠ°ΡΠ΅ΡΠΈΠ°Π»Π°
ΠΠ½ΡΠΎΡΠΌΠ°ΡΡΠΉΠ½Π΅ Π·Π°ΠΊΠΎΠ½ΠΎΠ΄Π°Π²ΡΡΠ²ΠΎ. ΠΡΠ½ΠΎΠ²Π½Ρ Π½ΠΎΡΠΌΠ°ΡΠΈΠ²Π½Ρ Π°ΠΊΡΠΈ
ΠΠ°Π²Π΅Π΄Π΅Π½ΠΎ ΠΎΡΠ½ΠΎΠ²Π½Ρ Π½ΠΎΡΠΌΠ°ΡΠΈΠ²Π½Ρ Π°ΠΊΡΠΈ Π· ΡΠ΅Π³ΡΠ»ΡΠ²Π°Π½Π½Ρ ΡΠ½ΡΠΎΡΠΌΠ°ΡΡΠΉΠ½ΠΈΡ
Π²ΡΠ΄Π½ΠΎΡΠΈΠ½, Π·ΠΎΠΊΡΠ΅ΠΌΠ°, Ρ ΡΡΠ΅ΡΡ ΡΠ½ΡΠΎΡΠΌΠ°ΡΡΡ, ΡΠ½ΡΠΎΡΠΌΠ°ΡΡΠΉΠ½ΠΈΡ
Π°Π³Π΅Π½ΡΡΡΠ², ΡΠ΅Π»Π΅ΠΊΠΎΠΌΡΠ½ΡΠΊΠ°ΡΡΡ,
ΡΠ°Π΄ΡΠΎΡΠ°ΡΡΠΎΡΠ½ΠΎΠ³ΠΎ ΡΠ΅ΡΡΡΡΡ Π£ΠΊΡΠ°ΡΠ½ΠΈ, ΡΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠ·Π°ΡΡΡ, ΡΠ΅Π»Π΅Π±Π°ΡΠ΅Π½Π½Ρ ΡΠΎΡΠΎ.
Π ΠΎΠ·ΡΠ°Ρ
ΠΎΠ²Π°Π½ΠΎ Π½Π° ΡΡΡΠ΄Π΅Π½ΡΡΠ², ΡΠΊΡ Π·Π΄ΠΎΠ±ΡΠ²Π°ΡΡΡ Π²ΠΈΡΡ ΠΎΡΠ²ΡΡΡ Π² Π³Π°Π»ΡΠ·ΡΡ
Π·Π½Π°Π½Ρ "ΠΡΠ°Π²ΠΎ", "ΠΠ½ΡΠΎΡΠΌΠ°ΡΡΠΉΠ½Π° Π±Π΅Π·ΠΏΠ΅ΠΊΠ°", "ΠΠΎΠΌΠΏ'ΡΡΠ΅ΡΠ½Ρ Π½Π°ΡΠΊΠΈ", "Π’Π΅Π»Π΅ΠΊΠΎΠΌΡΠ½ΡΠΊΠ°ΡΡΡ"
Proposing the Interactivity-Stimulus-Attention Model (ISAM) to Explain and Predict the Enjoyment, Immersion, and Adoption of Purely Hedonic Systems
Traditional TAM research primarily focuses on utilitarian systems where extrinsic motivations chiefly explain and predict acceptance. We propose a theoretical model, ISAM, which explains the role of intrinsic motivations in building the user attention that leads to hedonic system acceptance. ISAM combines several theories with TAM to explain how interactivity acts as a stimulus in hedonic contextsβfostering curiosity, enjoyment, and the full immersion of cognitive resources. Two experiments involving over 700 participants validated ISAM as a useful model for explaining and predicting hedonic system acceptance. Immersion and PE are shown to be the primary predictors of behavioral intention to use hedonic systems. Unlike traditional utilitarian adoption research, PEOU does not directly impact BIU, and extrinsic motivations are virtually non-existent. The implications of this study extend beyond hedonic contexts, as users of utilitarian systems continue to demand more hedonic features and enjoyment is often more important than PEOU
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