20 research outputs found

    DeepSaucer: Unified Environment for Verifying Deep Neural Networks

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    In recent years, a number of methods for verifying DNNs have been developed. Because the approaches of the methods differ and have their own limitations, we think that a number of verification methods should be applied to a developed DNN. To apply a number of methods to the DNN, it is necessary to translate either the implementation of the DNN or the verification method so that one runs in the same environment as the other. Since those translations are time-consuming, a utility tool, named DeepSaucer, which helps to retain and reuse implementations of DNNs, verification methods, and their environments, is proposed. In DeepSaucer, code snippets of loading DNNs, running verification methods, and creating their environments are retained and reused as software assets in order to reduce cost of verifying DNNs. The feasibility of DeepSaucer is confirmed by implementing it on the basis of Anaconda, which provides virtual environment for loading a DNN and running a verification method. In addition, the effectiveness of DeepSaucer is demonstrated by usecase examples

    Verifying a signature architecture: a comparative case study

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    We report on a case study in applying different formal methods to model and verify an architecture for administrating digital signatures. The architecture comprises several concurrently executing systems that authenticate users and generate and store digital signatures by passing security relevant data through a tightly controlled interface. The architecture is interesting from a formal-methods perspective as it involves complex operations on data as well as process coordination and hence is a candidate for both data-oriented and process-oriented formal methods. We have built and verified two models of the signature architecture using two representative formal methods. In the first, we specify a data model of the architecture in Z that we extend to a trace model and interactively verify by theorem proving. In the second, we model the architecture as a system of communicating processes that we verify by finite-state model checking. We provide a detailed comparison of these two different approaches to formalization (infinite state with rich data types versus finite state) and verification (theorem proving versus model checking). Contrary to common belief, our case study suggests that Z is well suited for temporal reasoning about process models with complex operations on data. Moreover, our comparison highlights the advantages of proving theorems about such models and provides evidence that, in the hands of an experienced user, theorem proving may be neither substantially more time-consuming nor more complex than model checkin

    The Effects of Different Force Directions and Resistance Levels during Unilateral Resistive Static Contraction of the Lower Trunk Muscles on the Ipsilateral Soleus H-reflex in the Side-lying Position

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    The objective of this study was to compare the effects of resistive static contraction of the pelvic depressor (RSCPD) with different direction–strength combinations on the H-reflex of the ipsilateral soleus. The participants were 16 normal subjects with a mean (SD) age of 21.6 (0.8) years. The subjects performed RSCPD under four distinct direction–strength combinations (straight-weak, straight-strong, diagonal-weak, and diagonal-strong) in a random order. Three-way analysis of variance of the H/Mmax ratio and Scheffé\u27s post-hoc test revealed that the RSCPD caused an initial reflexive facilitatory phase on the H-reflex of the soleus during RSCPD followed by subsequent gradual inhibitory phases after completion of the RSCPD, excluding the interval 80–100 s after RSCPD. Compared with diagonal-weak RSCPD, neutral-strong RSCPD also significantly influenced the facilitatory effects on the H-reflex of the soleus, reflecting facilitation of the reflex excitability of the motor neurons

    The effects of opposite-directional static contraction of the muscles of the right upper extremity on the ipsilateral right soleus H-reflex

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    The objective of this study was to explore the neurophysiological remote after-effects of resistive static contraction (SC) of the muscles of the upper extremity, considering the resistant direction on the ipsilateral (right) soleus H-reflex. The participants included 12 normal subjects with a mean (SD) age of 23.8 (2.8) years. The subjects were asked to maintain their upper extremity against the traction force, at a level of resistance that was 50% of the maximal SC strength. A 20-s SC of the muscles of the upper extremity utilizing contraction of the upper extremity muscles using a diagonal flexion (shoulder flexion-adduction-external rotation) or extension (shoulder extension-abduction-internal rotation), a proprioceptive neuromuscular facilitation (PNF) pattern was induced. The traction force line of the diagonal flexion or extension direction ran parallel to the diagonal line from the left acromion process to the right ASIS. Three-way analysis of variance of the H/Mmax ratio with Scheffé’s post-hoc tests revealed that the H/Mmacorrelatex ratio of SC via diagonal extension was significantly smaller than that via diagonal flexion and that the H/Mmax ratio during the 120–140 s phase after SC, as remote after-effect SC, was significantly smaller than that during SC. The induction of neurophysiological descending effects for inhibition requires consideration of the force direction

    Topologically-protected single-photon sources with topological slow light photonic crystal waveguides

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    Slow light waveguides are advantageous for implementing high-performance single-photon sources required for scalable operation of integrated quantum photonic circuits (IQPCs), though such waveguides are known to suffer from propagation loss due to backscattering. A way to overcome the drawback is to use topological photonics, in which robust waveguiding in topologically-protected optical modes has recently been demonstrated. Here, we report single-photon sources using single quantum dots (QDs) embedded in topological slow light waveguides based on valley photonic crystals. We observe Purcell-enhanced single-photon emission from a QD into a topological slow light mode with a group index over 20 and its robust propagation even under the presence of sharp bends. These results pave the way for the realization of robust and high-performance single-photon sources indispensable for IQPCs

    Comparison between bracing and hollowing trunk exercise with a focus on the change in T2 values obtained by magnetic resonance imaging.

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    The purpose of this study was to compare the muscle activity of Bracing and Hollowing trunk exercises by means of T2 values using MRI. Subjects were 19 healthy adult males, of whom 10 (with mean height ± SD: 172.3 ± 4.7 cm, mean weight ± SD: 64.3 ± 5.4 kg, mean age ± SD 21.5 ± 1.9 years) performed hollowing and 9 (with mean height ± SD: 171.3 ± 2.1 cm, mean weight ± SD: 68.5 ± 11.7 kg, mean age ± SD: 23.0 ± 2.6 years) performed bracing. They were assessed using MRI. The imaging was completed using Osirix software, which measured T2 values from the transversus abdominis (TrA), internal oblique (IO), external oblique (EO), and multifidus (MF) muscles. Subsequently, T2 values recorded before the exercise were compared with those recorded after the exercise to evaluate the extent of change effected by exercise on the muscles. MRI T2 values indicated that the TrA and IO regions were activated to a significantly greater degree after bracing. No significant changes occurred in any muscle before and after hollowing. It was determined that the activity of the deeper trunk muscles was higher in bracing than in hollowing on comparing the T2 values obtained in the MRI
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