• Pediatric Infection and Vaccine
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• v.31 no.1
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• pp.147-152
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• 2024

There have been several case reports of neurological manifestations in pediatrics as severe acute respiratory syndrome coronavirus-2 infection in children is being increased. We report a case of a 4-year-old boy who presented febrile seizure during follow-up in a negative pressure isolation room after confirmed coronavirus disease 2019, which has not yet been reported in Korea. He has no symptoms other than fever. The seizure was controlled after one dose of intravenous lorazepam, and there was no respiratory support during the hospitalization. He was discharged 12 days later without neurological sequelae.

• Journal of Radiation Protection and Research
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• v.37 no.4
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• pp.202-207
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• 2012

The radioactivity inventory significantly affects all steps of decommissioning projects including planning, cost estimation, risk assessment, waste management and site remediation. The decommissioning project of the KRR-2 was completed in 2009 and a large amount of activated concrete waste was generated. The bioshield concrete, containing minute amount of impurity elements, was activated by neutron reaction during the operation of the reactor. A variety radionuclides was generated in the concrete, including $^3H$, $^{14}C$, $^{55}Fe$, $^{60}Co$ $^{63}Ni$, $^{134}Cs$, $^{152}Eu$ and $^{154}Eu$. In this paper, the comparison between the calculated results and previous measured results was carried out to estimate the inventory of the bioshield concrete of the KRR-2. The combined computer codes of MCNP5 and ORIGEN 2.1 for calculation of the distribution of neutron flux, cross-section and generation of radionuclides were used. The results were shown that 99.8% of the total radioactivity of $^3H$, $^{55}Fe$, $^{60}Co$ and $^{152}Eu$ in the bioshield concrete 12 years after shutdown. The effects on the variation of inventory were analysed depending on the operation periods and the cooling times in the bioshield concrete.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.1-12
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• 2017

A natural hybrid of interspecific between the Coreoleuciscus splendidus and C. aeruginos (Cypriniformes: Cyprinidae) was captured in the Hwang-ji Stream, a tributary of the Nakdong River basin in Korea. An interspecific hybrid between C. splendidus and C. aeruginos was genetically identified based on morphological characteristics and the sequence analysis of nuclear recombination activating gene 1 (RAG1) gene (1,334 bp) and mitochondrial cytochrome c oxidase subunit 1 (CO1) gene (1,551 bp). As a result of morphological variations, the natural hybrid appeared to have an intermediate character between two parental species (C. splendidus and C. aeruginos) in three variations of black array (s) on dorsal, caudal and anal fin rays. Phylogenetic analysis inferred from RAG1 and CO1 sequence data revealed that Coreoleuciscus populations from Hwang-ji stream consist of two pure Coreoleuciscus species and a hybrid individual group. The individuals were clearly identified the cross and reciprocal hybrid by CO1 gene analysis. In RAG1 gene, 13 nucleotide variation loci were detected and the hybrid individuals displayed the double peaks of sequence chromatograms at the 9 diagnostic positions. In this study, molecular data and morphological variations were clearly demonstrated that hybridization did occur between C. splendidus and C. aeruginos. However, F2 hybrid generation and reproductive capacity of F1 hybrid individuals were not demonstrated.

• Economic and Environmental Geology
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• v.53 no.6
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• pp.793-807
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• 2020

The policy for Green New Deal will promote the shift of the application to coal as feedstock from coal as fuel. Coal can be used as fuel for production of hydrogen and as feedstock materials such as synthetic graphite or activated carbon. Hydrogen is obtained from syngas produced through Steam carbon(SC), Water-Gas Shift(WGS), and Carbonation reactions, and these processes should be used in conjunction with CO2 sequestration technology. Anthracite has a potential in terms of cost advantage as a feedstock compared to a petroleum pitch, because Synthetic graphite is prepared by heat treating an anthracite with high rank to a graphitization temperature which is in the range of 2400~2800℃, in the presence of inorganic catalyst such as silicon or iron. From several studies, it has been confirmed that coal-based activated carbon(AC) is manufactured with quality similar to the large specific surface area and much micropore volume of lignin-based AC, can be prepared. Therefore it is expected that lignin-based AC is replaced to coal-based AC.

• Korean Chemical Engineering Research
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• v.47 no.5
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• pp.531-537
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• 2009

Climate changes including environmental disasters after reckless industrialization have been globally witnessed. Considerable attention on the imminent need for developing CCS(Carbon dioxide Capture and Storage) methodologies to minimize the emission thus has been given. Chemical absorption is particularly regarded important because of its commercial availability and applicability to large scale plants. This paper addresses recent trends of chemical absorption technologies and the need for the further research on the topic from the perspective of process systems engineering(PSE).

• Journal of the Microelectronics and Packaging Society
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• v.11 no.2 s.31
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• pp.43-47
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• 2004

A coupler or divider is a microwave passive component used for power coupling or dividing. Regarding the trend of current telecommunication systems monolithic integration of passive components is highly desirable. In this study by the LTCC(Low temperature co-fired ceramics) technology a 2012 size type dual band coupler with multi-layer structure was fabricated. To achieve the desired coupling values for both DCS and EGSM bands, broad side coupled patterns were used with multi-layer structure. Its characteristics such as coupling, insertion loss, isolation and directivity values were measured and compared with simulation results.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.1
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• pp.42-52
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• 2013

Carbon Capture and Storage (CCS) is a mitigation technology essential in tackling global climate change. In Korea, many research projects are aimed to commercialize CCS business around 2020. Public acceptance can be a key factor to affect the successful proceeds of CCS near future. Therefore this paper provides a concise insight into the application of environmental impact assessment and risk assessment procedures to support the sustainable CCS projects. Futhermore, bottlenecks regarding the environmental impacts assessment and related domestic and foreign legislation are revised. Finally, suggestions to overcome these bottlenecks and recommendations for future research are made in conclusion.

• Archives of design research
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• v.12 no.2
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• pp.19-28
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• 1999

Current technology does not emphasize closer connection through group collaboration, but rather underlines the distances and separations that are visible in today's society. As the interpretation of our territory of life which is still based on the model of the 'physical' of industrial era is no more valid, a different 'sense of belonging' corresponds to this new notion of territory. The main idea is how to make the sense of community to connect actual space with one child from each place. Therefore, the subject of this thesis is to design the system making children from distance to be closer, developing 'learning community' connecting with two classes across the globe. The contents include its studying in respect to the development of a non-geographical 'learning community' based on co-evolution, and to the system design of conceptual models for the community. In conclusion, the physical interface design is suggested to let user develop accurate mental models of the system.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.23 no.5
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• pp.109-114
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• 2023

In this paper, a 2-channel Image-Reject receiver using a 65-nm CMOS process is presented for Ka-band compact radars. The designed receiver consists of Low-Noise Amplifier (LNA), IQ mixer, and Analog Baseband (ABB). ABB includes a complex filter in order to suppress unwanted images, and the variable gain amplifiers (VGAs) in RF block and ABB have gain tuning range from 4.5-56 dB for wide dynamic range. The gain of the receiver is controlled by on-chip SPI controllers. The receiver has noise figure of <15 dB, OP1dB of >4 dBm, image rejection ratio of >30 dB, and channel isolation of >45 dB at the voltage gain of 36 dB, in the Ka-band target frequency. The receiver consumes 420 mA at 1.2 V supply with die area of 4000×1600 ㎛.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.2
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• pp.194-201
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• 2010

We propose a frequency selective surface(FSS) using double split ring resonators(DSRRs) for isolation enhancement between CDMA and RFID. The structure consists of an outer SRR and an inner SRR, and the gaps are formed in the same direction. By properly adjusting the gap and line width, the resonant frequency and skirt characteristics can be adjusted without varying the unit cell size. The proposed structure has a different field distribution from that of an ordinary SRR for magneto-dielectric materials. One layer consists of $9{\times}9$ unit cells and the other layer was separated by 50 mm. To validate the simulation results, we fabricated the patch antenna and the FSSs, and the measured results show a good agreement with the simulated ones. The electrical size of the unit cell is $0.110\;{\lambda}{\times}0.110\;{\lambda}{\times}0.002\;{\lambda}$, and the size of the two layer FSS is $1.058\;{\lambda}{\times}1.058\;{\lambda}{\times}0.153\;{\lambda}$. The two layer FSS maintain gain in CDMA frequency and has 6.9 dB reduced gain in RFID frequency.