• Applied Science and Convergence Technology
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• v.25 no.2
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• pp.32-35
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• 2016

Using conventional deposition techniques, we demonstrate a method to fabricate ultra-smooth 10 nm silver films without using a wetting layer or co-depositing another material. The argon working pressure plays a crucial role in achieving an excellent surface flatness for silver films deposited by DC magnetron sputtering on an InP substrate. The formation of ultra-smooth silver thin films is very sensitive to the argon pressure. At the optimum deposition condition, a uniform silver film with an rms surface roughness of 0.81 nm has been achieved.

• ETRI Journal
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• v.42 no.5
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• pp.721-733
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• 2020

Recently, there is an increasing demand for ultra-low-latency (ULL) services such as factory automation, autonomous driving, and telesurgery that must meet an end-to-end latency of less than 10 ms. Fifth-generation (5G) New Radio guarantees 0.5 ms one-way latency, so the feasibility of ULL services is higher than in previous mobile communications. However, this feasibility ensures performance at the radio access network level and requires an innovative 5G network architecture for end-to-end ULL across the entire 5G system. Hence, we survey in detailed two the 3rd Generation Partnership Party (3GPP) standardization activities to ensure low latency at network level. 3GPP standardizes mobile edge computing (MEC), a low-latency solution at the edge network, in Release 15/16 and is standardizing time-sensitive communication in Release 16/17 for interworking 5G systems and IEEE 802.1 time-sensitive networking (TSN), a next-generation industry technology for ensuring low/deterministic latency. We developed a 5G system based on 3GPP Release 15 to support MEC with a potential sub-10 ms end-to-end latency in the edge network. In the near future, to provide ULL services in the external network of a 5G system, we suggest a 5G-IEEE TSN interworking system based on 3GPP Release 16/17 that meets an end-to-end latency of 2 ms.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.12 s.177
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• pp.42-50
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• 2005

This paper presents an ultra precision machining system using a high sensitive force sensing module to measure machining forces and penetration displacement in a tip-based nanopatterning. The force sensing module utilizes a leaf spring mechanism and a capacitive displacement sensor and it has been designed to provide a measuring range from 80 ${\mu}N$ to 8 N. This force sensing module is mounted on a PZT driven in-feed motion stage with 1 nm resolution. The sample can be moved by X-Y scanning motion stage with 5 nm resolution. In nano indentation experiments and patterning experiments, the machining forces were controlled and monitored by the force sensing module. Then, the patterned samples were measured by AFM. Experimental results demonstrated that the developed system can be used as an effective device in nano indentation and nanopatterning operation.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1095-1100
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• 2000

Concrete structure often exhibit cracks due to the combination of material construction and design error. Minor crack can be tolerated depending on exposure condition, but major cracks are aesthetically unpleasant and affect the durability and safety of the structure. All of the reinforced concrete structure have many inevitable cracks for various reason such as drying shrinkage, heat liberation of cement and over loads. Epoxy resin injection widely used for repairing cracks in concrete is too sensitive to high temperature. Besides, the problem in the epoxy resin injection is the difficulty of quality control after execution. Whereas, Ultra Fine Cement is similar in coefficient of thermal expansion and modulus of elasticity to concrete. The objective of the study is to find out that it is possible for Ultra Fine Cement to be used for repairing cracks in reinforced concrete.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.05a
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• pp.131-131
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• 2009

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.228.2-228.2
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• 2014

Characteristics of high Fermi velocity, high mechanical strength, and transparency offer tremendous advantages for using graphene as a promising transparent conducting material [1] in electronic devices. Although graphene is a prospective candidate for touch sensor with strong mechanical properties [2] and flexibility, only few investigations have been carried out in the field of sensor as a device form. In this study, we suggest ultra-highly sensitive and transparent graphene touch sensor fabricated by single layer graphenes. One of the graphene layers is formed in the top panel as a disconnected graphene beam transferred on PDMS, and the other of the graphene layer is formed with line-patterning on the bottom panel of triple structure PET/PI/SiO2. The touch sensor shows characteristics of flexible. Its transmittance is approximately 75% where transmittance of the top panel and the bottom panel are 86.3% and 87%, respectively, at 550 nm wavelength. Sheet resistance of each graphene layer is estimated as low as $971{\Omega}/sq$. The results show that the conductance change rate (${\Delta}C/C0$) is $8{\times}105$ which depicts ultra-high sensitivity. Moreover, reliability characteristic confirms consistent behavior up to a 100-cycle test.

• Biomedical Science Letters
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• v.18 no.3
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• pp.276-282
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• 2012

High-intensive endurance exercises induce cell changes in body, changes in structures and functions of the heart, the muscles, the cartilages, and the liver, as well as increase of inflammatory cytokine. The purpose of this study was to estimate the biochemical changes in the liver and muscles during ultra-marathon race (100 km) by sections. The blood of the subjects was collected before the marathon as a control in order to analyze serum creatine kinase (CK), lactic dehydrogenase (LDH), asprtate aminotransferase (AST), alanine aminotransferase (ALT), total(T)-bilirubin, direct(D)-bilirubin, total protein, albumin, uric acid, gamma-glutamyltranspeptidase (${\gamma}$-GTP), alkaline phosphatase (ALP), creatinine, blood urea nitrogen (BUN), and high sensitive C-reactive protein (hs-CRP) concentrations. The CK, LDH, D-bilirubin, AST and ALT concentrations at 50 km and 100 km were significantly increased compared to the control (P<0.05). The markers at 100 km were higher than those at 50 km (P<0.05). The T-bilirubin and hs-CRP concentrations showed no difference among the groups, whereas the markers at 100 km were higher than those of the control and at 50 km (P<0.05). In conclusion, this study shows that the ultra-marathon race (100 km) may induce the damage of the skeletal muscle, liver and kidney, intravascular hemolysis and inflammatory responses.

• Journal of Veterinary Science
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• v.22 no.3
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• pp.40.1-40.12
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• 2021

Background: The microsporidian parasite Nosema ceranae is a global problem in honeybee populations and is known to cause winter mortality. A sensitive and rapid tool for stable quantitative detection is necessary to establish further research related to the diagnosis, prevention, and treatment of this pathogen. Objectives: The present study aimed to develop a quantitative method that incorporates ultra-rapid real-time quantitative polymerase chain reaction (UR-qPCR) for the rapid enumeration of N. ceranae in infected bees. Methods: A procedure for UR-qPCR detection of N. ceranae was developed, and the advantages of molecular detection were evaluated in comparison with microscopic enumeration. Results: UR-qPCR was more sensitive than microscopic enumeration for detecting two copies of N. ceranae DNA and 24 spores per bee. Meanwhile, the limit of detection by microscopy was 2.40 × 10⁴ spores/bee, and the stable detection level was ≥ 2.40 × 10⁵ spores/bee. The results of N. ceranae calculations from the infected honeybees and purified spores by UR-qPCR showed that the DNA copy number was approximately 8-fold higher than the spore count. Additionally, honeybees infected with N. ceranae with 2.74 × 10⁴ copies of N. ceranae DNA were incapable of detection by microscopy. The results of quantitative analysis using UR-qPCR were accomplished within 20 min. Conclusions: UR-qPCR is expected to be the most rapid molecular method for Nosema detection and has been developed for diagnosing nosemosis at low levels of infection.

• The Korean Journal of Nuclear Medicine Technology
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• v.19 no.1
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• pp.72-80
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• 2015

Purpose Serum estradiol ($E_2$) measurement is requested for diagnosing menstrual cycles, ovulation induction, infertility, and menopause. $E_2$ is measured using several methods and kits including radioimmunoassay (RIA) and chemiluminescece immunoassay (CLIA). The purpose of this study was to evaluate quality of these methods and to compare them with each other. Materials and Methods Seven radioimmunoassay kits and two CLIA methods were included in the analysis. Using standard samples and patient samples, intra-assay precision, inter-assay precision, correlation between other methods, sensitivity, and recovery rate were evaluated. Results For all tested kits and methods, coefficients of variance (CVs) of intra-assay precision test were 10.9~13.6% in low-level samples and less than 10% in medium and high-level samples. CVs of inter-assay precision test were 10.8~12.3% in low-level samples and less than 10% in medium and high-level samples with all tested kits and methods. Recovery rates were $92.7{\pm}12.4%$ for SIEMENS, $101.4{\pm}18.4%$ for DIAsource, $95.1{\pm}11.5%$ for AMP, $108.4{\pm}18.5%$ for BECKMAN COULTER, $104.2{\pm}13.5%$ for BECKMAN COULTER Ultra Sensitive, $101.3{\pm}11.6%$ for CIS Bio, and $93.1{\pm}13.2%$ for MP kits. Sensitivity was 7.5, 6.2, 5.7, 6.2, 5.3, 4.5, and 5.5 pg/mL for SIEMENS, DIAsource, AMP, BECKMAN COULTER, BECKMAN COULTER Ultra Sensitive, CIS Bio, and MP kits, respectively. The measurement by MP kit was slightly higher than those by other kits in low-level samples, and the measurement by E170 was slightly higher than those of other kits in medium and high-level samples. In the measurement of standard sample for external quality control, SIEMENS kit produced relatively lower values whereas E170, Architect, and MP kits produced relatively higher values compared with other kits. Conclusion All tested kits for $E_2$ measurement have satisfactory performance for clinical use. However, correlation between kits should be considered when test kits are to be changed, because some pairs of kits do not have correlations with each other.

• Journal of Veterinary Science
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• v.21 no.1
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• pp.4.1-4.9
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• 2020

Fast and accurate detection of viral RNA pathogens is important in apiculture. A polymerase chain reaction (PCR)-based detection method has been developed, which is simple, specific, and sensitive. In this study, we rapidly (in 1 min) synthesized cDNA from the RNA of deformed wing virus (DWV)-infected bees (Apis mellifera), and then, within 10 min, amplified the target cDNA by ultra-rapid qPCR. The PCR products were hybridized to a DNA-chip for confirmation of target gene specificity. The results of this study suggest that our method might be a useful tool for detecting DWV, as well as for the diagnosis of RNA virus-mediated diseases on-site.