• International Journal of Computer Science & Network Security
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• v.21 no.6
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• pp.252-257
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• 2021

The application of the principle of trigeneration allows to simultaneously provide electricity to power electronic devices, as well as heat and cold to create the necessary microclimate of the premises and increase efficiency compared to separate cooling and heating systems. The use of Peltier thermoelectric modules (TEM) as part of trigenerative systems allows for smooth and precise control of the temperature regime, high manufacturability and reliability due to the absence of moving parts, resistance to shock and vibration, and small weight and size parameters of the system. One of the promising areas of improvement of trigenerative systems is their modeling and optimization based on the automatic control theory. A block diagram and functional model of an energy-saving trigenerative climate control system based on Peltier modules are developed, and the transfer functions of an open and closed system are obtained. The simulation of the transient characteristics of the system with varying parameters of the components is performed. The directions for improving the quality of transients in the climate control system are determined, as well as the prospects of the proposed methodology for modeling and analyzing control systems operating in substantially nonlinear modes.

• The Plant Pathology Journal
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• v.38 no.2
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• pp.102-114
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• 2022

Pectobacterium carotovorum subsp. carotovorum (Pcc) is a gram-negative, broad host range bacterial pathogen which causes soft rot disease in potatoes as well as other vegetables worldwide. While Pectobacterium infection relies on the production of major cell wall degrading enzymes, other virulence factors and the mechanism of genetic adaptation of this pathogen is not yet clear. In the present study, we have performed an in-depth genome-wide characterization of Pcc strain ICMP5702 isolated from potato and compared it with other pathogenic bacteria from the Pectobacterium genus to identify key virulent determinants. The draft genome of Pcc ICMP5702 contains 4,774,457 bp with a G + C content of 51.90% and 4,520 open reading frames. Genome annotation revealed prominent genes encoding key virulence factors such as plant cell wall degrading enzymes, flagella-based motility, phage proteins, cell membrane structures, and secretion systems. Whereas, a majority of determinants were conserved among the Pectobacterium strains, few notable genes encoding AvrE-family type III secretion system effectors, pectate lyase and metalloprotease in addition to the CRISPR-Cas based adaptive immune system were uniquely represented. Overall, the information generated through this study will contribute to decipher the mechanism of infection and adaptive immunity in Pcc.

• Journal of Information Technology Services
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• v.20 no.6
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• pp.125-139
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• 2021

To explore college students' course satisfaction over the course of the semester during which a full-scale digital transformation was in progress due to COVID-19 pandemic, this study analyzed student survey data from a university located in the metropolitan area. To minimize the respondents' burden to answer long list of detailed questions in repetition, the study utilized a pulse survey method and students were asked to answer a brief and regular set of online questions 5 times throughout the semester. The number of survey respondents ranged from 1,640 to 4,116, with an average of more than 3,700. The main results and implications of this study are summarized as follows. First, the survey data indicated that the overall student satisfaction with online courses was above average (3.46/5). Vast majority of students have chosen pre-recorded, contents-based course over real-time, video-based course as their preferred course delivery method and this tendency remained the same throughout the semester. Second, the results of keyword network analysis of open-ended questions indicated that technical issues, increased workload (e.g., course assignments and course attendance) were main causes of online course dissatisfaction. And students suggested an unified online course platform and more interactive course design to further improve online courses in the future.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.3
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• pp.441-450
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• 2022

The introduction of autonomous underwater gliders (AUGs) specifically addresses the reduction of operational costs that were previously prohibited with conventional autonomous underwater vehicles (AUVs) using a "scaling-down" design philosophy by utilizing the characteristics of autonomous drifters to far extend operation duration and coverage. Long-duration, wide-area missions raise the cost and complexity of in-water testing for novel approaches to autonomous mission planning. As a result, a simulator that supports the rapid design, development, and testing of autonomy solutions across a wide range using software-in-the-loop simulation at faster-than-real-time speeds becomes critical. This paper describes a faster-than-real-time AUG simulator that can support high-resolution bathymetry for a wide variety of ocean environments, including ocean currents, various sensors, and vehicle dynamics. On top of the de facto standard ROS-Gazebo framework and open-sourced underwater vehicle simulation packages, features specific to AUGs for ocean mapping are developed. For vehicle dynamics, the next-generation hybrid autonomous underwater gliders (Hybrid-AUGs) operate with both the buoyancy engine and the thrusters to improve navigation for bathymetry mappings, e.g., line trajectory, are is implemented since because it can also describe conventional AUGs without the thrusters. The simulation results are validated with experiments while operating at 120 times faster than the real-time.

• Korean Journal of Materials Research
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• v.31 no.8
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• pp.465-470
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• 2021

Deuterium is a crucial clean energy source required for nuclear fusion and is a future resource needed in various industries and scientific fields. However, it is not easy to enrich deuterium because the proportion of deuterium in the hydrogen mixture is scarce, at approximately 0.016 %. Furthermore, the physical and chemical properties of the hydrogen mixture and deuterium are very similar. Therefore, the efficient separation of deuterium from hydrogen mixtures is often a significant challenge when using modern separation technologies. Recently, to effectively separate deuterium, studies utilizing the 'Kinetic Quantum Sieving Effect (KQS)' of porous materials are increasing. Therefore, in this review, two different strategies have been discussed for improving KQS efficiency for hydrogen isotope separation performance using nanoporous materials. One is the gating effect, which precisely controls the aperture locally by adjusting the temperature and pressure. The second is the breathing phenomenon, utilizing the volume change of the structure from closed system to open system. It has been reported that efficient hydrogen isotope separation is possible using these two methods, and each of these effects is described in detail in this review. In addition, a specific-isotope responsive system (e.g., 2nd breathing effect in MIL-53) has recently been discovered and is described here as well.

• Earthquakes and Structures
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• v.22 no.2
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• pp.157-168
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• 2022

A moment-independent importance measure analysis approach was introduced to quantify the effects of structural uncertainty parameters on probabilistic seismic demands of simply supported girder bridges. Based on the probability distributions of main uncertainty parameters in bridges, conditional and unconditional bridge samples were constructed with Monte-Carlo sampling and analyzed in the OpenSees platform with a series of real seismic ground motion records. Conditional and unconditional probability density functions were developed using kernel density estimation with the results of nonlinear time history analysis of the bridge samples. Moment-independent importance measures of these uncertainty parameters were derived by numerical integrations with the conditional and unconditional probability density functions, and the uncertainty parameters were ranked in descending order of their importance. Different from Tornado diagram approach, the impacts of uncertainty parameters on the whole probability distributions of bridge seismic demands and the interactions of uncertainty parameters were considered simultaneously in the importance measure analysis approach. Results show that the interaction of uncertainty parameters had significant impacts on the seismic demand of components, and in some cases, it changed the most significant parameters for piers, bearings and abutments.

• BMB Reports
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• v.55 no.2
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• pp.72-80
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• 2022

Odorant receptors (ORs), the largest subfamily of G protein-coupled receptors, detect odorants in the nose. In addition, ORs were recently shown to be expressed in many nonolfactory tissues and cells, indicating that these receptors have physiological and pathophysiological roles beyond olfaction. Many ORs are expressed by tumor cells and tissues, suggesting that they may be associated with cancer progression or may be cancer biomarkers. This review describes OR expression in various types of cancer and the association of these receptors with various types of signaling mechanisms. In addition, the clinical relevance and significance of the levels of OR expression were evaluated. Namely, levels of OR expression in cancer were analyzed based on RNA-sequencing data reported in the Cancer Genome Atlas; OR expression patterns were visualized using t-distributed stochastic neighbor embedding (t-SNE); and the associations between patient survival and levels of OR expression were analyzed. These analyses of the relationships between patient survival and expression patterns obtained from an open mRNA database in cancer patients indicate that ORs may be cancer biomarkers and therapeutic targets.

• Journal of Marine Bioscience and Biotechnology
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• v.14 no.2
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• pp.143-154
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• 2022

We isolated marine actinomycetes, strain D-5 which produces anti-methicillin resistant Staphylococcus aureus (anti-MRSA) compound. Streptomyces sp. D-5 relatively grew well in the 20~25℃, pH 8.0, and NaCl 3.0%. The ethyl acetate extract of D-5 culture was separated by C₁₈ ODS open column and reverse phase HPLC to yield anti-MRSA compound. The molecular weight of this compound was determined to be 898 by a Liquid chromatograph-mass spectrometer (LC-MS). Compared with penicillin G, this compound showed significant anti-MRSA activity. It also exhibited an inhibition zone of 26 mm at a concentration of 64 ㎍/disk and an inhibition zone of 16 mm at a concentration of 16 ㎍/disk against the MRSA KCCM 40511. Furthermore, the co-treatment of HPLC peak 5 compound and vancomycin caused a more rapid decrease in MRSA cells than each compound alone. It showed 86.8% growth inhibition activity within 12 hours at a low concentration of 50 ㎍/mL during co-treatment, and 97.1% growth in-hibition activity within 48 hours against MRSA KCCM 40511. Taken together, our results suggest that Streptomyces sp. D-5 and its anti-MRSA compound could be employed as a potent agent in MRSA infection.

• Natural Product Sciences
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• v.28 no.4
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• pp.181-186
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• 2022

A germacrane-type sesquiterpenoid was isolated and purified from a methanol extract of the roots of Valeriana fauriei (RVF) through open column chromatography using silica gel. This compound was verified to be heishuixiecaoline A by spectroscopic analysis. This compound was isolated for the first time from RVF. Quantitative analysis of heishuixiecaoline A from RVF cultivated from three different regions (Eumseong, Jinbu, and Jinan regions) was performed by combining high-performance liquid chromatography with a photodiode array detector. The extract of RVF cultivated in the Jinbu region showed the highest content (9.23 mg/g). In addition, a significant amount of the compound was detected in all RVF samples, which could be expected since it is a characteristic compound of RVF. The sesquiterpenoid group heishuixiecaoline A was isolated from RVF, a resource for various pharmacological substances, and quantitative analysis of RVF cultivated from three different regions was performed. As a result of these experiments, basic data on RVF that can be used in the development and application of pharmaceuticals and health functional foods in the future were obtained.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.147.2-148
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• 2003

Complete nucleotide sequence of genome RNA of a Korean isolate of Pepper mottle virus (PepMoV-Vb) from field-collected diseased paprika (Capsicum annuum var grossum) was determined in this study. Symptoms of isolates of PepMoV were divided largely into two groups, vein banding (Vb) and vein clearing (Vc) patterns. PepMoV-Vb RNA consists of 9,640 nucleotides excluding the poly(A) tail. A single open reading frame was identified beginning at nucleotide position 169 encoding a polyprotein of 3024 amino acids which is typical of the Potyvirus genus. The complete nucleotide sequence and coding regions of PepMoV-Vb were compared to that of 11 potyviruses within the genus Potyvirus. The overall nucleotide sequence identity was 94.7 and 94.1％ identical to PepMoV-C and PepMoV-FL, respectively. Full-length cDNAs of PepMoV-Vbl were synthesized from purified viral RNAs by RT-PCR and their genome structure was analysed by RFLP analysis. This is the first report on complete nucleotide sequence of PepMoV isolated from paprika in Korea.