73 research outputs found
Adversarial Finetuning with Latent Representation Constraint to Mitigate Accuracy-Robustness Tradeoff
This paper addresses the tradeoff between standard accuracy on clean examples
and robustness against adversarial examples in deep neural networks (DNNs).
Although adversarial training (AT) improves robustness, it degrades the
standard accuracy, thus yielding the tradeoff. To mitigate this tradeoff, we
propose a novel AT method called ARREST, which comprises three components: (i)
adversarial finetuning (AFT), (ii) representation-guided knowledge distillation
(RGKD), and (iii) noisy replay (NR). AFT trains a DNN on adversarial examples
by initializing its parameters with a DNN that is standardly pretrained on
clean examples. RGKD and NR respectively entail a regularization term and an
algorithm to preserve latent representations of clean examples during AFT. RGKD
penalizes the distance between the representations of the standardly pretrained
and AFT DNNs. NR switches input adversarial examples to nonadversarial ones
when the representation changes significantly during AFT. By combining these
components, ARREST achieves both high standard accuracy and robustness.
Experimental results demonstrate that ARREST mitigates the tradeoff more
effectively than previous AT-based methods do.Comment: Accepted by International Conference on Computer Vision (ICCV) 202
Improvement in the productivity of xylooligosaccharides from waste medium after mushroom cultivation by hydrothermal treatment with suitable pretreatment
The effective xylooligosaccharides (XOs) production from the waste medium after mushroom cultivation (WM) was investigated. The WM contains rich nutrients (protein, etc.) which induce Maillard reaction with reducing sugars under hydrothermal conditions. To improve the productivity of XOs, the suitable pretreatment combined with washing and grinding was investigated, and subsequently hydrothermal treatment was demonstrated with batch type and continuous flow type reactor. The washing pretreatment with hot water of 60 degrees C was effective to remove nutrients from the WM, and it led to prevent brownish discoloration on the hydrothermal treatment. On the basis of experimental data, industrial XOs production processes consisting of the pretreatment, hydrothermal treatment and purification step was designed. During the designed process, 2.3 kg-dry of the purified XOs was produced from 30 kg-wet of the WM (15% yield as dry basis weight). Theoretical yield of XOs attained to 48% as xylan weight in the WM.ArticleBioresource Technology. 101(15):6006-6011 (2010)journal articl
A Statistical Study of Gamma-Ray Emitting Solar Flares Observed with Yohkoh
Gamma-ray emitting solar flares observed with Yohkoh were analyzed from a
statistical viewpoint. The four-band hard X-ray (15--95 keV) photometric data,
taken with the Hard X-ray Telescope onboard Yohkoh, were utilized in
combination with the spectro-photometric gamma-ray (0.2--30 MeV) data obtained
with the Gamma-Ray Spectrometer. The GOES class was also incorporated. Out of
2788 X-ray flares observed from 1991 October to 2001 December, 178 events with
strong hard X-ray emission were selected. Among them, 40 flares were further
found to show significant gamma-ray emission. A fractal dimension analysis and
multi-band color--color plots of the 40 flares suggest that their soft X-ray to
MeV gamma-ray spectral energy distributions involve at least four independent
parameters. These are: (1) the overall flare size; (2) the relative intensities
of the thermal vs. non-thermal signals; (3) the gamma-ray to hard X-ray
intensity ratio; and (4) the hard X-ray spectral slope. These results are
examined for possible selection effects. Also, the meanings of the third
parameter are briefly considered.Comment: 23 pages, 7 figures, PASJ accepte
End-to-End Joint Target and Non-Target Speakers ASR
This paper proposes a novel automatic speech recognition (ASR) system that
can transcribe individual speaker's speech while identifying whether they are
target or non-target speakers from multi-talker overlapped speech.
Target-speaker ASR systems are a promising way to only transcribe a target
speaker's speech by enrolling the target speaker's information. However, in
conversational ASR applications, transcribing both the target speaker's speech
and non-target speakers' ones is often required to understand interactive
information. To naturally consider both target and non-target speakers in a
single ASR model, our idea is to extend autoregressive modeling-based
multi-talker ASR systems to utilize the enrollment speech of the target
speaker. Our proposed ASR is performed by recursively generating both textual
tokens and tokens that represent target or non-target speakers. Our experiments
demonstrate the effectiveness of our proposed method.Comment: Accepted at Interspeech 202
A Spectral Study of the Black Hole Candidate XTE J1752-223 in the High/Soft State with MAXI, Suzaku and Swift
We report on the X-ray spectral analysis of the black hole candidate XTE\
J1752--223 in the 2009--2010 outburst, utilizing data obtained with the
MAXI/Gas Slit Camera (GSC), the Swift/XRT, and Suzaku, which work
complementarily. As already reported by Nakahira et al. (2010) MAXI monitored
the source continuously throughout the entire outburst for about eight months.
All the MAXI/GSC energy spectra in the high/soft state lasting for 2 months are
well represented by a multi-color disk plus power-law model. The innermost disk
temperature changed from 0.7 keV to 0.4 keV and the disk flux
decreased by an order of magnitude. Nevertheless, the innermost radius is
constant at 41 km, where is the
source distance in units of 3.5 kpc and the inclination. The multi-color
disk parameters obtained with the MAXI/GSC are consistent with those with the
Swift/XRT and Suzaku. The Suzaku data also suggests a possibility that the disk
emission is slightly Comptonized, which could account for broad iron-K features
reported previously. Assuming that the obtained innermost radius represents the
innermost stable circular orbit for a non-rotating black hole, we estimate the
mass of the black hole to be 5.510.28 , where the correction for the stress-free inner boundary condition
and color hardening factor of 1.7 are taken into account. If the inclination is
less than 49 as suggested from the radio monitoring of transient jets
and the soft-to-hard transition in 2010 April occurred at 1--4% of Eddignton
luminosity, the fitting of the Suzaku spectra with a relativistic
accretion-disk model derives constraints on the mass and the distance to be
3.1--55 and 2.3--22 {\rm kpc}, respectively. This confirms that the
compact object in XTE J1752--223 is a black hole.Comment: 12 pages including 7 figures and 4 tables, accepted for publication
in PAS
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