• 한국지하수토양환경학회지:지하수토양환경
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• 제16권6호
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• pp.133-142
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• 2011

A total of 247 samples were collected from groundwater being used for drinking-water supply, and hydrogeochemistry and radionuclide analysis were performed. In-situ analysis of groundwaters resulted in ranges of $13.7{\sim}25.1^{\circ}C$ for temperature, 5.9~8.5 for pH, 33~591 mV for Eh, $66{\sim}820{\mu}S/cm$ for EC, and 0.2~9.4 mg/L for DO. Major cation and anion concentrations of groundwaters were in ranges of 0.5~227.6 for Na, 1.0~279.3 for Ca, 0.0~9.3 for K, 0.1~100.1 for Mg, 0.0~3.3 for F, 0.9~779.1 for Cl, 0.3~120.4 for $SO_4$, 0.0~27.4 for $NO_3$-N, and 6~372 mg/L for $HCO_3$. Uranium-238 and radon-222 concentrations were detected in ranges of N.D-$131.1{\mu}g/L$ and 18-15,953 pCi/L, respectively. In case of some groundwaters exceeding USEPA MCL level ($30{\mu}g/L$) for uranium concentration, their pH ranged from 6.8 to 8.0 and Eh showed a relatively low value(86~199 mV) compared to other areas. Most groundwaters belonged to Ca-(Na)-$HCO_3$ type, and groundwaters of metamorphic rock exhibited the highest concentration of Na, Mg, Ca, Cl, $NO_3$-N, U, and those of plutonic rock showed the highest concentration of $HCO_3$, and Rn. Uranium and fluoride from granite areas did not show any correlation. However, uranium and bicarbonate displayed a positive relation of some areas in plutonic rocks($R^2$=0.3896).

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.237-238
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• 2008

본 연구에서는 APD 소자 제작시 주로 쓰이는 RTA에 의한 Zn 확산방법에 사용할 경우 undoped InP의 V/III비율에 따른 Zn원자의 확산, 도핑, 오믹저항의 성장을 조사하였다. RTA에 의한 확산 및 활성화 열처리 시 도핑 농도의 프로파일은 확산열처리만 한 경우보다 활성화 처리한 경우 더 커짐을 볼 수 있었다. SIMS 결과 활성화 처리 후 표면쪽에 Zn원자의 약간의 결핍현상을 보이는 데 이는 표면쪽에 Zn원자의 탈착이 약간 이루어지는 것으로 보인다. 이 원인은 결과적으로 오믹저항의 증가를 가져왔다.

• 안보군사학연구
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• 통권8호
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• pp.169-238
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• 2010

The year 2010 is the 60th anniversary commemorating the Korean War. China intervened in the Korean War with the logics such as "To Resist the U.S.'s Aggression and Aid North Korea," "Save Endangered Home & defend Nation," and "If the Lips Are Gone, the Teeth Will Be Exposed to the Cold or If One of Them Falls, the Other is in Danger." However, China had a deep and long connection with North Korea through 1st Chinese Civil War, war against Japan imperialism, and 2nd Chinese Civil War. China has consulted with Kim Il-sung on his invasion of South Korea at the initial stage of development and played a casting vote role in the execution of the invasion plan. During the Korean War, the PLA supported the North Korea's regime by its action, and made the Korea Peninsula divide into two semi-permanently. Even after the war, China continues to maintain relations with North Korea by helping North Korea build the Kim Il-sung's Kingdom. Currently, whenever any issue related to North Korea rises in the international society, China definitely gets involved in those issues and exercises its power. Conditionally 'either armed aggression or, and wartime' in North Korea, China would follow the "Clause of Military Auto Intervention." In addition, China is very likely to establish refugee camps for North Koreans in the Northeastern-Three-Province and to provide rear bases or guerrilla camps for pro-Chinese sects. Furthermore, voluntarily playing a role as spokesman of North Korean Regime in the international society, China will exercise enormous influence on the reunification of the Korean Peninsula.

• 한국건축시공학회지
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• 제17권1호
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• pp.15-21
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• 2017

라돈은 토양이나 암석, 지하수 안에서 우라늄(U-238)이 핵분열 할 때 발생하는 무색, 무취, 무미의 반응성이 거의 없는 비활성 단원자 분자 기체로 반감기 동안 연쇄적으로 붕괴하는데 이때 방사성 핵종(Bi, Po, Pb)이 만들어 지며 이를 자손핵종이라 한다. 이는 공기 중의 먼지 등에 흡착하여 사람이 호흡할시 폐에 흡착하여 붕괴하는데 여기서 발생하는 알파선에 장기간 피폭하면 폐암을 유발하는 것으로 밝혀졌다. 이에 따라 실내공기질에 관한 기준과 연구가 지속적으로 시행되고 있는 실정이다. 본 연구는 실내 라돈가스를 최소화 하고 저감하기 위한 무시멘트계 흡착재를 연구개발 하기위한 기초실험으로 흡착재의 첨가량에 따라 유동성 및 강도는 저하되는 경향을 보였지만, 이는 흡착재의 밀도 및 공극에 의한 것으로 판단되며, 라돈가스 농도의 경우 첨가량 증가에 따라 감소하는 경향을 보였다. 향후 가장 적합한 흡착재를 활용하여 보다 세밀하고 다양한 실험이 이루어져야 할 것으로 판단되며, 경화체상의 기초실험을 통해 추후 건축 마감재에 관한 실험도 이루어져야 할 것이다.

• Nuclear Engineering and Technology
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• 제50권8호
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• pp.1324-1329
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• 2018

This study presents a practical application of complementary safety indicators, which can be applied in a safety assessment of a radioactive waste repository by excluding a biosphere simulation and comparing the artificial radiation originating from the repository with the background natural radiation. Complementary safety indicators (radiotoxicity flux from geosphere and radiotoxicity concentration in seawater) were applied in the safety assessment of a rock-cavern type low and intermediate level radioactive waste (LILW) repository in the Republic of Korea. The natural radionuclide ($^{40}K$, $^{226,228}Ra$, $^{232}Th$, and $^{234,235,238}U$) concentrations in the groundwater and seawater at the Gyeongju LILW repository site were measured. Based on the analyzed concentrations of natural radionuclides, the levels of natural radiation were determined to be $8.6{\times}10^{-5}$ - $8.0{\times}10^{-4}Sv/m^2/yr$ and $6.95{\times}10^{-5}Sv/m^3$ for radiotoxicity flux from the geosphere and radiotoxicity concentration in seawater, respectively. From simulation results obtained using a Goldsim-based safety assessment model, it was determined that the radiotoxicity of radionuclides released from the repository is lower than that of the natural radionuclides inherently present in the natural waters. The applicability of the complementary safety indicators to the safety case was discussed with regard to reduction of the uncertainty associated with biosphere simulations, and communication with the public.

• 한국컴퓨터정보학회논문지
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• 제26권1호
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• pp.231-238
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• 2021

이 논문은 Covid-19 이후 기간의 빅데이터를 활용하여 일상에서 주문하는 음식 배달과 소비의 경향을 분석하는 방법을 제시한다. 빅데이터를 분석하고 데이터베이스 시스템을 이용하여, 날씨를 제외한 네 개의 요소들이 배달의민족 매출과 의미있는 상관관계가 있는 것으로 확인되었다. 이 연구는 KBS, MBC와 SBS 언론매체의 빅데이터 분석에서 Covid-19 관련 기사 다음 날에 음식 배달과 소비 증가가 거의 60%에 달하는 것을 발견하였다. 또한 Naver 검색결과에서도 Covid-19 관련 기사 다음 날에 심각하게 의미있는 음식 배달과 소비 증가를 발견하였다. 그 이외에, 소비의 흐름에 있어서 모바일을 통한 배달이 주류가 될 것이며 밀레니얼 세대가 대세가 될 것이라는 것도 알 수 있었다. 본 연구는 방대하고 구체적인 데이터를 사용하여 똑같은 방법으로 경기 침체기에 다른 산업 분야에 대하여 분석을 가능하게 하는 것으로, 기업의 입장에서 발빠른 대응으로 경기 침체 속의 호황을 맞이할 수 있는 분석과 방법을 제공하는 데 기여할 수 있다.

• Nuclear Engineering and Technology
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• 제54권4호
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• pp.1431-1438
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• 2022

In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K were 93, 77, 92 and 938 Bq kg^-1, respectively. The average results for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y^-1, respectively. The average emanation fraction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30×10^-3, 4.26×10^-3, 0.62×10^-3, and 25.61×10^-3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2733-2742
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• 2020

This paper presents an assessment of applicability of the multigroup cross sections generated with Monte Carlo tools to the fast reactor analysis based on transport calculations. 33-group cross section sets were generated for simple one- (1-D) and two-dimensional (2-D) sodium-cooled fast reactor problems using the SERPENT code and applied to deterministic steady-state and depletion calculations. Relative to the reference continuous-energy SERPENT results, with the transport corrected P₀ scattering cross section, the k-eff value was overestimated by 506 and 588 pcm for 1-D and 2-D problems, respectively, since anisotropic scattering is important in fast reactors. When the scattering order was increased to P₅, the 1-D and 2-D problem errors were increased to 577 and 643 pcm, respectively. A sensitivity and uncertainty analysis with the PERSENT code indicated that these large k-eff errors cannot be attributed to the statistical uncertainties of cross sections and they are likely due to the approximate anisotropic scattering matrices determined by scalar flux weighting. The anisotropic scattering cross sections were alternatively generated using the MC²-3 code and merged with the SERPENT cross sections. The mixed cross section set consistently reduced the errors in k-eff, assembly powers, and nuclide densities. For example, in the 2-D calculation with P3 scattering order, the k-eff error was reduced from 634 pcm to -223 pcm. The maximum error in assembly power was reduced from 2.8% to 0.8% and the RMS error was reduced from 1.4% to 0.4%. The maximum error in the nuclide densities at the end of 12-month depletion that occurred in ²³⁷Np was reduced from 3.4% to 1.5%. The errors of the other nuclides are also reduced consistently, for example, from 1.1% to 0.1% for ²³⁵U, from 2.2% to 0.7% for ²³⁸Pu, and from 1.6% to 0.2% for ²⁴¹Pu. These results indicate that the scalar flux weighted anisotropic scattering cross sections of SERPENT may not be adequate for application to fast reactors where anisotropic scattering is important.

• Archives of Plastic Surgery
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• 제49권1호
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• pp.121-126
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• 2022

Background Although they may not replace standard training methods that use surgical microscopes, smartphones equipped with high-resolution screens and high-definition cameras are an attractive alternative for practicing microsurgical skills. They are ubiquitous, simple to operate, and inexpensive. This study compared anastomoses of chicken femoral vessels using a smartphone camera versus a standard operative microscope. Methods Forty anastomoses of non-living chicken femoral vessels were divided into four groups. A resident and an experienced microsurgeon performed anastomoses of femoral chicken vessels with 8-0 and 10-0 sutures, using a smartphone camera and a surgical microscope. The time to complete the anastomosis and the number of anastomosis errors were compared using the Mann-Whitney U test. Results The time taken to perform an anastomosis by the experienced microsurgeon was significantly longer when using the smartphone (median: 32.5 minutes vs. 20 minutes, P<0.001). The resident completed the anastomoses with both types of equipment without a significant difference in the operative times. When using a smartphone, the operation times were not significantly different between the resident and the experienced microsurgeon (P=0.238). The resident showed non-significant differences in operation time and the number of errors when using a smartphone or an operative microscope (P=1.000 and P=0.065, respectively). Conclusions Microsurgical practice with non-living chicken femoral vessels can be performed with a smartphone, though it can take longer than with an operative microscope for experienced microsurgeons. The resident may also experience frustration and tend to make more anastomosis errors when using a smartphone versus an operative microscope.

• Clinical and Experimental Pediatrics
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• 제65권5호
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• pp.230-238
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• 2022

Myocarditis was previously attributed to an epidemic viral infection. Additional harmful reagents, in addition to viruses, play a role in its etiology. Coronavirus disease 2019 (COVID-19) vaccine-induced myocarditis has recently been described, drawing attention to vaccine-induced myocarditis in children and adolescents. Its pathology is based on a series of complex immune responses, including initial innate immune responses in response to viral entry, adaptive immune responses leading to the development of antigen-specific antibodies, and autoimmune responses to cellular injury caused by cardiomyocyte rupture that releases antigens. Chronic inflammation and fibrosis in the myocardium eventually result in cardiac failure. Recent advancements in molecular biology have remarkably increased our understanding of myocarditis. In particular, microRNAs (miRNAs) are a hot topic in terms of the role of new biomarkers and the pathophysiology of myocarditis. Myocarditis has been linked with microRNA-221/222 (miR-221/222), miR-155, miR-10a^*, and miR-590. Despite the lack of clinical trials of miRNA intervention in myocarditis yet, multiple clinical trials of miRNAs in other cardiac diseases have been aggressively conducted to help pave the way for future research, which is bolstered by the success of recently U.S. Food and Drug Administration-approved small-RNA medications. This review presents basic information and recent research that focuses on myocarditis and related miRNAs as a potential novel biomarker and the therapeutics.