• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.48 no.12
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• pp.1013-1020
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• 2020

Spark-induced breakdown spectroscopy (SIBS) utilizes an electric spark to induce a strong plasma for collecting atomic emissions. This study analyses the potential for usinga compact SIBS instead of conventional laser-induced breakdown spectroscopy (LIBS) in discriminating rocks and soils for planetary missions. Targeting bulky solids using SIBS has not been successful in the past, and therefore a series of optimizations of electrode positioning and electrode materials were performed in this work. The limit of detection (LOD) was enhanced up to four times compared to when LIBS was used, showing a change from 78 to 20 ppm from LIBS to SIBS. Because of the higher energy of plasma generated, the signal intensity by SIBS was higher than LIBS in three orders of magnitude with the same spectrometer setup. Changing the electrode material and locating the optimum position of the electrodes were considered for optimizing the current SIBS setup being tested for samples of planetary origin.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2592-2598
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• 2022

Research groups in the field of PET instrumentation are studying time-of-flight(TOF) technology to improve the signal-to-noise ratio of PET images. Scintillation light transport and collection plays an important role in improving the coincidence resolving time(CRT) of PET detector based on a pixelated crystal array. Four crystal arrays were designed by the different optical reflection configuration such as external reflectors and surface treatment on the CRT and compared with the light output, energy resolution and CRT. The design proposed in the study was composed of 8 × 8 LYSO crystal array consisted of 3 × 3 × 15 mm³ pixels. The entrance side was roughened while the other five surfaces were polished. Four sides of all crystal pixels were wrapped with ESR-film, and the entrance surface was covered by Teflon-tape. The design provided an excellent timing resolution of 210 ps and improved the CRT by 16% compared to the conventional method using a polishing treatment and ESR-film. This study provided a method for improving the light output and CRT of a pixelated scintillation crystal-based brain TOF PET detector. The proposed configuration might be an attractive detector design for TOF brain PET requiring fast timing performance with high cost-effectiveness.

• Nuclear Engineering and Technology
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• v.54 no.7
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• pp.2444-2452
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• 2022

The field-programmable gate array (FPGA) is gaining popularity in industrial automation such as nuclear power plant instrumentation and control (I&C) systems due to the benefits of having non-existence of operating system, minimum software errors, and minimum common reason failures. Separate functions can be processed individually and in parallel on the same integrated circuit using FPGAs in comparison to the conventional microprocessor-based systems used in any plant operations. The use of FPGAs offers the potential to minimize complexity and the accompanying difficulty of securing regulatory approval, as well as provide superior protection against obsolescence. Wireless sensor networks (WSNs) are a new technology for acquiring and processing plant data wirelessly in which sensor nodes are configured for real-time signal processing, data acquisition, and monitoring. ZigBee (IEEE 802.15.4) is an open worldwide standard for minimum power, low-cost machine-to-machine (M2M), and internet of things (IoT) enabled wireless network communication. It is always a challenge to follow the specific topology when different Zigbee nodes are placed in a large network such as a plant. The research article focuses on the hardware chip design of different topological structures supported by ZigBee that can be used for monitoring and controlling the different operations of the plant and evaluates the performance in Vitex-5 FPGA hardware. The research work presents a strategy for configuring FPGA with ZigBee sensor nodes when communicating in a large area such as an industrial plant for real-time monitoring.

• Molecules and Cells
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• v.45 no.6
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• pp.413-424
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• 2022

Suppressor of mothers against decapentaplegic homolog (SMAD) 4 is a pluripotent signaling mediator that regulates myriad cellular functions, including cell growth, cell division, angiogenesis, apoptosis, cell invasion, and metastasis, through transforming growth factor β (TGF-β)-dependent and -independent pathways. SMAD4 is a critical modulator in signal transduction and functions primarily as a transcription factor or cofactor. Apart from being a DNA-binding factor, the additional SMAD4 mechanisms in tumor suppression remain elusive. We previously identified methyl malonyl aciduria cobalamin deficiency B type (MMAB) as a critical SMAD4 binding protein using a proto array analysis. This study confirmed the interaction between SMAD4 and MMAB using bimolecular fluorescence complementation (BiFC) assay, proximity ligation assay (PLA), and conventional immunoprecipitation. We found that transient SMAD4 overexpression down-regulates MMAB expression via a proteasome-dependent pathway. SMAD4-MMAB interaction was independent of TGF-β signaling. Finally, we determined the effect of MMAB downregulation on cancer cells. siRNA-mediated knockdown of MMAB affected cancer cell metabolism in HeLa cells by decreasing ATP production and glucose consumption as well as inducing apoptosis. These findings suggest that SMAD4 controls cancer cell metabolism by regulating MMAB.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.1
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• pp.188-210
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• 2022

As a promising technique to support tremendous numbers of Internet of Things devices and a variety of applications efficiently, mobile edge computing (MEC) has attracted extensive studies recently. In this paper, we consider a MEC-assisted peer-to-peer (P2P) mobile communication system where MEC servers are deployed at access points to accelerate the communication process between mobile terminals. To capture the tradeoff between the time delay and the energy consumption of the system, a cost function is introduced to facilitate the optimization of the computation and communication resources. The formulated optimization problem is non-convex and is tackled by an iterative block coordinate descent algorithm that decouples the original optimization problem into two subproblems and alternately optimizes the computation and communication resources. Moreover, the MEC-assisted P2P communication system is compared with the conventional P2P communication system, then a condition is provided in closed-form expression when the MEC-assisted P2P communication system performs better. Simulation results show that the advantage of this system is enhanced when the computing capability of the receiver increases whereas it is reduced when the computing capability of the transmitter increases. In addition, the performance of this system is significantly improved when the signal-to-noise ratio of hop-1 exceeds that of hop-2.

• Applied Chemistry for Engineering
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• v.33 no.5
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• pp.451-458
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• 2022

Semiconductor quantum dots (QDs) are optical probes with excellent fluorescence properties. Therefore, they have been applied to various bio-medical imaging techniques and biosensors. Due to the unique optical characteristics of wide absorption and narrow fluorescence energy bands, multiple types of signals can be generated by the combination of fluorescence wavelengths from different QDs, which enables the simultaneous detection of more than two biomarkers. In this review, the advantages and applications of QDs and QD nanobeads (QBs) in multiple biomarker assays were described, and new developments or improvements in multiplexed biomarker detection techniques were summarized. In particular, recent reports were summarized, focusing on the design strategies in immunoassay construction and signal transducing materials for fluorescence-linked immunosorbent assays using QDs and immunochromatographic assays using QBs. New detection platforms will be developed for early diagnosis of diseases and other fields if multiplexed detection technologies of excellent accuracy and sensitivity are combined with artificial intelligence algorithms.

• Plant Journal
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• v.18 no.2
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• pp.41-45
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• 2022

The conventional communication method using mud flow pressure waves has a speed of 1-2 bps, so it takes a long time to communicate, making real-time control impossible. Although the sound wave communication method for improving the communication speed by 10 times or more has been commercialized, its use is limited due to its high price and there are not many application cases. In this study, the simulator corresponding to the facility was developed to develop performance similar to the actual test results. For simulating sound wave communication through a drill pipe, we proposed a governing equation that can simulate friction damping by mud and developed a numerical analysis model. The attenuation factor was corrected by comparing it with the attenuation rate of sound wave energy at the drilling site. The developed numerical analysis model was applied to the QPSK modulation type communication algorithm to confirm the excellent performance of the communication error rate of 0.04% in the ground. This is the communication performance under the condition that noise has not been mixed yet, and in order to apply it, the technology of reproducing the actual noise signal for mixing by securing the field noise data was established.

• Journal of Veterinary Science
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• v.23 no.5
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• pp.72.1-72.14
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• 2022

Background: The treatment of acute kidney injury (AKI), a common disease in dogs, is limited. Therefore, an effective method to prevent AKI in veterinary clinics is particularly crucial. Objectives: Hydrogen sulfide (H₂S) is the third gaseous signal molecule involved in various physiological functions of the body. The present study investigated the effect of H₂S on cisplatin-induced AKI and the involved mechanisms in dogs. Methods: Cisplatin-injected dogs developed AKI symptoms as indicated by renal dysfunction and pathological changes. In the H₂S-treated group, 50 mM sodium hydrosulfide (NaHS) solution was injected at 1 mg/kg/h for 30 min before cisplatin injection. After 72 h, tissue and blood samples were collected immediately. We performed biochemical tests, optical microscopy studies, analysis with test kits, quantitative reverse-transcription polymerase chain reaction, and western blot analysis. Results: The study results demonstrated that cisplatin injection increased necroptosis and regulated the corresponding protein expression of receptor interacting protein kinase (RIPK) 1, RIPK3, and poly ADP-ribose polymerase 1; furthermore, it activated the expressions of inflammatory factors, including tumor necrosis factor-alpha, nuclear factor kappa B, and interleukin-1β, in canine kidney tissues. Moreover, cisplatin triggered oxidative stress and affected energy metabolism. Conversely, an injection of NaHS solution considerably reduced the aforementioned changes. Conclusions: In conclusion, H₂S protects the kidney from cisplatin-induced AKI through the mitigation of necroptosis and inflammation. These findings provide new and valuable clues for the treatment of canine AKI and are of great significance for AKI prevention in veterinary clinics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1457-1462
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• 2021

Untact order payment has become a new normal since the COVID-19. BLE beacon is a technology that supports low-power wireless communication within 70 meters without Bluetooth pairing and is specialized for indoor positioning. Therefore, it is suitable for building and providing O2O services beyond B2C and B2B services. However, beacons have a lower utilization rate because they have fewer platforms than wifi that support long-distance wireless communication. Therefore, this paper aims to provide more convenient non-face-to-face related services than before by designing and proposing an O2O service platform using BLE beacons. When scanning beacons, not only does it receive advertising data that beacons have, but it also ensures that the actual distance between the user's terminal and beacons is accurately calculated. Through accurate location, the O2O service platform will be able to provide users with store information, such as coupons and discounts, museum exhibits, and traffic information at the right time.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.3
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• pp.171-176
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• 2022

The communication signal for quick cut-off specification is defined as "design to support fast cut-off requirements of all applicable photovoltaic(PV) systems" in NEC 2014, NEC 2017 or the corresponding UL standard regardless of the system configuration. On the other hand, if you look at the domestic regulations related to new and renewable energy, the standards, regulations, and guidelines set by each institution are general, or only the parts necessary for the institution are being established and operated. There are many insufficient points to apply these things to photovoltaic facilities, and there are cases where excessive facilities are installed according to the design, inspection standards of supervisors and inspection agencies, and the skill level of inspectors. The internationally accepted IEC standards deal with various facility standards in detail. In each European country, there are separate facility regulations based on IEC. In particular, the performance and safety of devices are dealt with in detail, and in the case of 'NEC Article 690' applied in North America such as the United States, each item is described in detail. Therefore, in this paper, we will look at the details of the PV shutdown technology that is currently used and applied internationally.