19,906 research outputs found
Development of accuracy enhancement system for boron meters using multisensitive detector for reactor safety
Boric acid is used as a coolant for pressurized-water reactors, and the degree of burnup is controlled by the concentration of boric acid. Therefore, accurate measurement of the concentration of boric acid is an important factor in reactor safety. An improved system was proposed for the accurate determination of boron concentration. A new boron-concentration measurement technique, called multisensitive detection, was developed to improve the measurement accuracy of boron meters. In previous studies, laboratory-scale experiments were performed based on different sensitivity detectors, confirming a 65% better accuracy than conventional single-detector boron meters. Based on these experimental results, an experimental system simulating the coolant-circulation environment in the reactor was constructed; accuracy analysis of the boron meter with a multisensitivity detector was performed at the actual coolant pressure and temperature. In this study, the boron concentration conversion equation was derived from the calibration test, and the accuracy of the boron concentration conversion equation was examined through a repeatability test. Through the experiment, it was confirmed that the accuracy was up to 87.5% higher than the conventional single-detector boron meter
Functional analysis of a gene encoding threonine synthase from rice
Threonine synthase (TS) is a pyridoxal phosphate dependent enzyme that catalyzes the formation of threonine (Thr) through O-phosphohomoserine (OPH) from the aspartate family pathway in plants. The properties of the TS enzyme have been evaluated in many bacteria and few plants. Sequence analysis of the cDNA from rice revealed that it harbors a full-length open reading frame for OsTS encoding for 521 amino acids, corresponding to a protein of approximately 57.2 kD. The predicted amino acid sequence of OsTS is highly homologous to that of Arabidopsis TS and many bacterial TS encoded by thrC gene. The OsTS protein harbors a signature binding motif for pyridoxal- 5’ -phosphate at the amino terminus. A thrC mutant strain of Escherichia coli was complemented by OsTS expression. OsTS expression was correlated with the survival of the thrC mutant, which is affected by thesupplementation of an aspartate pathway metabolite, methionine
Restoration of the JPEG Maximum Lossy Compressed Face Images with Hourglass Block based on Early Stopping Discriminator
When a JPEG image is compressed using the loss compression method with a high
compression rate, a blocking phenomenon can occur in the image, making it
necessary to restore the image to its original quality. In particular,
restoring compressed images that are unrecognizable presents an innovative
challenge. Therefore, this paper aims to address the restoration of JPEG images
that have suffered significant loss due to maximum compression using a
GAN-based net-work method. The generator in this network is based on the U-Net
architecture and features a newly presented hourglass structure that can
preserve the charac-teristics of deep layers. Additionally, the network
incorporates two loss functions, LF Loss and HF Loss, to generate natural and
high-performance images. HF Loss uses a pretrained VGG-16 network and is
configured using a specific layer that best represents features, which can
enhance performance for the high-frequency region. LF Loss, on the other hand,
is used to handle the low-frequency region. These two loss functions facilitate
the generation of images by the generator that can deceive the discriminator
while accurately generating both high and low-frequency regions. The results
show that the blocking phe-nomenon in lost compressed images was removed, and
recognizable identities were generated. This study represents a significant
improvement over previous research in terms of image restoration performance
PP-GAN : Style Transfer from Korean Portraits to ID Photos Using Landmark Extractor with GAN
The objective of a style transfer is to maintain the content of an image
while transferring the style of another image. However, conventional research
on style transfer has a significant limitation in preserving facial landmarks,
such as the eyes, nose, and mouth, which are crucial for maintaining the
identity of the image. In Korean portraits, the majority of individuals wear
"Gat", a type of headdress exclusively worn by men. Owing to its distinct
characteristics from the hair in ID photos, transferring the "Gat" is
challenging. To address this issue, this study proposes a deep learning network
that can perform style transfer, including the "Gat", while preserving the
identity of the face. Unlike existing style transfer approaches, the proposed
method aims to preserve texture, costume, and the "Gat" on the style image. The
Generative Adversarial Network forms the backbone of the proposed network. The
color, texture, and intensity were extracted differently based on the
characteristics of each block and layer of the pre-trained VGG-16, and only the
necessary elements during training were preserved using a facial landmark mask.
The head area was presented using the eyebrow area to transfer the "Gat".
Furthermore, the identity of the face was retained, and style correlation was
considered based on the Gram matrix. The proposed approach demonstrated
superior transfer and preservation performance compared to previous studies
Expression of a natural fusion gene for uracil phosphoribosyltransferase and uridine kinase from rice shows growth retardation by 5-fluorouridine or 5- fluorouracil in Escherichia coli
Uridine kinase (UK) and uracil phosphoribosyltransferase (UPRT) are enzymes in pyrimidine salvage pathway. UK or UPRT were reported as separate genes in bacteria. Amino acid sequence of OsUK/UPRT1 from rice shows homology to bacterial enzymes. Amino-terminal region is similar to UDK with an ATP/GTP-binding motif, whereas the carboxyl-terminal similar to UPP with two binding motifs for a uracil and a PRPP, respectively. Expression of  OsUK/UPRT1 in an udk and/or upp mutant of Escherichia coli led to growth inhibition with 5-fluorouridine or 5-fluorouracil. These results suggestthat the OsUK/UPRT1 product would be a natural fusion protein of two enzymes
The Impact of Tax Treaties on Foreign Direct Investment: The Evidence Reconsidered
This paper reconsiders the empirical evidence of the relationship between tax treaties and FDI using U.S. outbound FDI to 78 countries over the period of 2007–2018. Unlike previous studies, we explicitly consider differences in the tax environments of recipient economies, including their tax-haven status, transfer pricing rules, CFC rules and anti-avoidance regulations, in our estimations. Our results confirm the importance of controlling for country-specific tax environments, especially the tax-haven status and transfer pricing rules. We find that tax treaties positively contribute to FDI inflows in developing countries, while they have no statistically significant impacts on OECD countries.
Recently signed tax treaties still foster FDI but less than older ones do.
Finally, our results indicate, all other things being equal, that the weaker the transfer pricing regulations, the greater the amount of U.S.
direct investment into a non-OECD economy
Particulate counter electrode system for enhanced light harvesting in dye-sensitized solar cells
A particulate counter electrode with photo scattering and redox catalytic properties is applied to dye sensitized solar cells (DSSCs) in order to improve photo conversion efficiency and simplify the assembly process. Our particulate counter electrode acts as both a photo reflecting layer and a catalyst for reduction of electrolyte. The reflective and catalytic properties of the electrode are investigated through optical and electrochemical analysis, respectively. A short circuit current density enhancement is observed in the DSSCs without the need to add an additional reflecting layer to the electrode. This leads to a simplified assembly process. (C) 2013 Optical Society of Americ
On matrices which have signed null-spaces
AbstractWe denote by Q(A) the set of all matrices with the same sign pattern as A. A matrix A has signed null-space provided there exists a set S of sign patterns such that the set of sign patterns of vectors in the null-space of A is S, for each A∈Q(A). We show that if A is an m by n matrix with no duplicate columns up to multiplication by −1 and A has signed null-space, then n⩽3m−2. We also classify the set of matrices satisfying the equality
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