• The Journal of Society for e-Business Studies
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• v.26 no.1
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• pp.127-140
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• 2021

Recently, sequence data containing time information, such as sensor measurement data and purchase history, has been generated in various applications. So far, many methods for finding sequences that are significantly different from other sequences among given sequences have been proposed. However, most of them have a limitation that they consider only the order of elements in the sequences. Therefore, in this paper, we propose a new anomalous sequence detection method that considers both the order of elements and the time interval between elements. The proposed method uses an extended LSTM autoencoder model, which has an additional layer that converts a sequence into a form that can help effectively learn both the order of elements and the time interval between elements. The proposed method learns the features of the given sequences with the extended LSTM autoencoder model, and then detects sequences that the model does not reconstruct well as anomalous sequences. Using experiments on synthetic data that contains both normal and anomalous sequences, we show that the proposed method achieves an accuracy close to 100% compared to the method that uses only the traditional LSTM autoencoder.

• Nuclear Engineering and Technology
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• v.54 no.5
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• pp.1674-1685
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• 2022

The ball valve is an important device in the pipeline transportation system of nuclear power plants. Its operational stability and safety directly affect the normal working of nuclear power plants. In this study, the transient numerical simulation of the opening and closing process of a ball valve was conducted on the basis of the flow interruption capability experiment of the ball valve by using the moving mesh method and inlet and outlet variable boundary conditions. The flow rate and pressure difference with time of the opening and closing process of the ball valve were studied. The internal flow characteristics of the ball valve under different relative openings were analyzed in conjunction with the typical back-step flow structure. Results show that the transient numerical results agree well with the experimental results. The internal flow characteristics of the ball valve are similar at the same opening during opening and closing process. At small opening, the spool and outlet channels easily form a back-step flow structure. The disappearance and generation of backflow vortices during opening and closing occur at 85% opening and 75% opening, respectively. With the decrease in opening degree, the difference in vortex core area in the flow channel of the ball valve spool in the opening and closing process gradually appears. The research results provide some reference value for the design and optimization of ball valves.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.6
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• pp.1137-1148
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• 2021

The main obstacle for implementing CSIDH-based cryptography is that it requires generating a kernel of a small prime order to compute the group action using Velu's formula. As this is a quite painstaking process for small torsion points, a new approach called radical isogeny is recently proposed to compute chains of isogenies from a coefficient of an elliptic curve. This paper presents an optimized implementation of radical isogenies and analyzes its ideal use in CSIDH-based cryptography. We tailor the formula for transforming Montgomery curves and Tate normal form and further optimized the radical 2- and 3- isogeny formula and a projective version of radical 5- and 7- isogeny. For CSIDH-512, using radical isogeny of degree up to 7 is 15.3% faster than standard constant-time CSIDH. For CSIDH-4096, using only radical 2-isogeny is the optimal choice.

• Journal of the Korean Applied Science and Technology
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• v.39 no.5
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• pp.632-643
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• 2022

Although probiotics have been shown to improve health when consumed, recent studies have reported that they can cause unwanted side effects due to bacterial-human interactions. Therefore, the importance of prebiotics that can form beneficial microbiome in the gut has been emphasized. This study isolated and identified bacteria capable of producing biopoymer as a candidate prebiotic from traditional fermented foods. The isolated and identified strain was named WCYSK01 (Wissella sp. strain YSK01). The composition of the medium for culturing this strain was prepared by dissolving 3 g K₂HPO₄, 0.2 g MgSO₄, 0.05 g CaCl₂, 0.1 g NaCl in 1 L of distilled water. The LMBP(low molecular weight biopoymers) produced when fermentation was performed with sucrose and maltose as substrates were mainly consisted of DP3 (degree of polymer; isomaltotriose), DP4 (isomaltotetraose), DP5 (isomaltopentaose), and DP6 (isomaltoheptaose). The optimization of LMBP (low molecular weight of biopolymer) production was performed using the response surface methodology. The fermentation process temperature range of 18 to 32℃, the fermentation medium pH in the range of 5.1 to 7.9. The yield of LMBP production by the strain was found to be significantly affected by q fermentation temperature and pH. The optimal fermentation conditions were found at the normal point, and the production yield was more than 75% at pH 7.5 and temperature of 23℃.

• Journal of Chest Surgery
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• v.55 no.5
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• pp.364-377
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• 2022

An anatomical understanding of the atrial myocardium is crucial for surgeons and interventionists who treat atrial arrhythmias. We reviewed the anatomy of the inter-nodal and intra-atrial conduction systems. The anterior inter-nodal route (#1) arises from the sinus node and runs through the ventral wall of the atrial chambers. The major branch of route #1 approaches the atrioventricular node from the anterior aspect. Other branches of route #1 are Bachmann's bundle and a vestibular branch around the tricuspid valve. The middle inter-nodal route (#2) begins with a broad span of fibers at the sinus venarum and extends to the superior limbus of the oval fossa. The major branch of route #2 joins with the branch of route #1 at the anterior part of the atrioventricular node. The posterior inter-nodal route (#3) is at the terminal crest and gives rise to many branches at the pectinate muscles of the right atrium and then approaches the posterior atrioventricular node after joining with the vestibular branch of route #1. The branches of the left part of Bachmann's bundle and the branches of the second inter-nodal route form a thin myocardial network at the posterior wall of the left atrium. These anatomical structures could be categorized into major routes and side branches. There are 9 or more anatomical circles in the atrial chambers that could be structural sites for macro re-entry. The implications of normal and abnormal structures of the myocardium for the pathogenesis and treatment of atrial arrhythmias are discussed.

• Journal of Korean Academy of Nursing
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• v.52 no.2
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• pp.228-243
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• 2022

Purpose: The study aimed to translate the Couple Satisfaction Index (CSI 32) into Korean, to evaluate the reliability and validity of CSI 32 and short-form (CSI 16, 4) in the Korean context, and to determine a cut-off score for Korean couples. Methods: Korean Versions of the Couple Satisfaction Index (K-CSI) 32 was translated, back-translated, and reviewed by five bilingual experts. Confirmatory factor analysis (CFA) was conducted with data from a sample of 218 couples (N = 436) to test construct validity. Validity and reliability were evaluated. The receiver's operating characteristics curve analysis was used to obtain the cut-off score. Results: The construct validities of K-CSI 32, 16, and 4 were verified using one-factor structures. The results of CFA showed a slightly better fit for K-CSI 16 and 4 than for K-CSI 32. Convergent validity was supported by significant positive correlations of K-CSI with Kansas Marital Satisfaction Scale, Dyadic Adjustment Scale, and Family Relationship Assessment Scale. Moreover, the significant differences in K-CSI between normal and depressive group demonstrated known-group validity. Cut-off scores of 105.5 on K-CSI 32, 50.25 on K-CSI 16, and 13.25 on K-CSI 4 were validated to identify distressed couple relationships. Conclusion: For clinical practice, the reliable and valid K-CSI 32 has the potential to measure changes in couple satisfaction after couple therapy or interventions. Applying K-CSI 32 may facilitate research on couple and family relationships in nursing and contribute to the discussion on the role of couple satisfaction in mental health.

• The Korea Journal of Herbology
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• v.35 no.2
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• pp.47-53
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• 2020

Objectives : Bombyx batryticatus L. is the dried larval form of the silkworm (Bombyx mori L.) infected by Beauveria bassiania (Bals.) Vuill. It is used as a food and medicinal resource to treat asthma, headaches, epilepsy, and convulsions in traditional Korean and Chinese medicines. However, the research of the toxicity about B. batryticatus is not enough yet. Here, we investigate the effects of potential subacute toxicity following the repeated oral administration of B. batryticatus water extract to C57BL/6 mice, at various doses of 0, 50, 150, and 450 mg/kg/day during a two-week period. Methods : The following parameters were examined during the study period: body weight, gross findings, clinical signs, organ weight, hematology, serum biochemistry, histopathology, and mortality. At the end of the treatment period, all the mice were euthanized. Results : No changes were observed in the body weights, gross findings, clinical signs, organ weights, and mortality after two weeks of administration of the B. batryticatus extract. In addition, compared with the normal control group, no noticeable treatment-related changes were observed in the hematological, serum biochemical, and histopathological parameters in the treated group following treatment with doses of up to 450 mg/kg/day. Conclusion : Based on these findings, we conclude that the treatment of mice with the water extract of B. batryticatus did not cause considerable C57BL/6 toxicity, and therefore, it could be considered safe for further pharmacological studies.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.367-372
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• 2022

The effect of the addition of a polyvinylchloride (PVC) non-solvent to a PVC-tetrahydrofuran (THF) solution on the surface properties of the PVC thin film was analyzed. The non-solvents used were composed of alcohol-based and non-alcoholic ones. Surface morphologies of PVC thin films according to the addition of the non-solvent were compared. In addition, the hydrophobic properties relying on the surface characteristics were compared. The micro-bubbles generated in the preparation of PVC-THF solution affected the surface morphology of the thin film. In order to implement the normal surface physical properties of the coating thin film at the relatively high concentration of PVC-THF solution, the selection of appropriate drying method was required. When an alcohol-based non-solvent was added, a PVC thin film having a granular porous surface was obtained and exhibited super hydrophobic properties. The volume ratio of the PVC-THF solution to the non-solvent affects the surface shape of the coating thin film. The larger the amount of non-solvent was added, the more advantageous it was to form a super hydrophobic PVC thin film.

• Industry Promotion Research
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• v.7 no.4
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• pp.109-119
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• 2022

In recent years, China's Internet finance industry is hot. There is no doubt that Internet finance has been fully integrated into China, forming a new form of financing, and rapidly becoming a new channel for investment and financing in China, shouldering the responsibility of inclusive financing and building China's real economy. However, with investment, there are risks. Based on the panel data of China's Internet financial platform, this paper uses the random effect model to study the influencing factors of Internet financial risks, and draws three conclusions: (1) The user funds and platform funds of the financial platform will be managed separately by the bank, which can effectively reduce the risk of financial transactions on the Internet; (2) The risk of Internet financial transactions can be effectively reduced by avoiding the concentration of platform funds in the hands of a few borrowers through regulatory policies; (3) The liquidity control of funds effectively reduces the risk of Internet financial transactions. Based on the conclusions, we propose optimization strategies for regulatory policies to achieve the healthy and sustainable development of Internet finance.

• Journal of Veterinary Science
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• v.21 no.6
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• pp.88.1-88.13
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• 2020

Background: Listeria monocytogenes is a gram-positive bacterium that causes listeriosis mainly in immunocompromised hosts. It can also cause foodborne outbreaks and has the ability to adapt to various environments. Peptide uptake in gram-positive bacteria is enabled by oligopeptide permeases (Opp) in a process that depends on ATP hydrolysis by OppD and F. Previously a putative protein Lmo2193 was predicted to be OppD, but little is known about the role of OppD in major processes of L. monocytogenes, such as growth, virulence, and biofilm formation. Objectives: To determine whether the virulence traits of L. monocytogenes are related to OppD. Methods: In this study, Lmo2193 gene deletion and complementation strains of L. monocytogenes were generated and compared with a wild-type strain for the following: adhesiveness, invasion ability, intracellular survival, proliferation, 50% lethal dose (LD₅₀) to mice, and the amount bacteria in the mouse liver, spleen, and brain. Results: The results showed that virulence of the deletion strain was 1.34 and 0.5 orders of magnitude higher than that of the wild-type and complementation strains, respectively. The function of Lmo2193 was predicted and verified as OppD from the ATPase superfamily. Deletion of lmo2193 affected the normal growth of L. monocytogenes, reduced its virulence in cells and mice, and affected its ability to form biofilms. Conclusions: Deletion of the oligopeptide transporter Lmo2193 decreases the virulence of L. monocytogenes. These effects may be related to OppD's function, which provides a new perspective on the regulation of oligopeptide transporters in L. monocytogenes.