• 융합정보논문지
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• 제11권7호
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• pp.104-110
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• 2021

본 핀 채널 전계 효과 트랜지스터에서 낮은 소스/드레인 직렬 저항을 위한 새로운 선택적 산화 방식을 제안하였다. 이 방법을 이용하면, gate-all-around 구조와 점진적으로 증가되는 형태의 소스/드레인 확장영역을 갖는 핀 채널 MOSFET를 얻을 수 있다. 제안된 트랜지스터는 비교 소자에 비해 70% 이상의 소스/드레인 직렬 저항의 감소를 얻을 수 있다. 또한, 제안된 소자는 단채널 효과를 억제하면서도 높은 구동 전류와 전달컨덕턴스 특징을 보인다. 제작된 소자의 포화전류, 최대 선형 전달컨덕턴스, 최대 포화 전달컨덕턴스, subthreshold swing, 및 DIBL은 각각 305 ㎂/㎛, 0.33 V, 13.5 𝜇S, 76.4 𝜇S, 78 mV/dec, 62 mV/V의 값을 갖는다.

• 농업과학연구
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• 제47권4호
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• pp.1135-1145
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• 2020

The purpose of this study was to compare and analyze the emissions of SOx and NH3 for a 78 kW class agricultural tractor during agricultural operations. A real-time monitoring system was constructed for measuring the load data. The field test was conducted during plow and rotary tillage. The working conditions were selected with the transmission gears in M3 Low and M2 High for the plow tillage and L3 High and L3 Low for the rotary tillage. The engine torque and fuel consumption were measured using controller area network (CAN) communication, and the emissions of SOx and NH3 were calculated based on the fuel consumption. As a result of the field tests, the engine torque was higher for the plow tillage than for the rotary tillage. As the gear stage was increased, the engine torque became higher. The emissions of SOx and NH3 were higher for the plow tillage than for the rotary tillage because the fuel consumption increased. Moreover, the emissions of SOx and NH3 tended to be more distributed for the rotary tillage than for the plow tillage. To develop an emission factor for agricultural machinery, it is important to measure reliable emission data during agricultural operations. In a future study, we will collect various emission data using a portable emission measurement system during agricultural operations.

• 정보보호학회논문지
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• 제21권4호
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• pp.101-114
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• 2011

산업스파이 및 악의적인 내부 이용자에 의한 기업 내부 핵심 정보유출 사건이 증대되고 있는 현실을 반영하듯, 감사 및 로그 보안기술의 중요성이 한층 부각되고 있는 것이 현실이다. 본 논문에서는 기업의 중요 정보를 처리하는 운영체제에 접속한 사용자에 대한 행위를 면밀히 감시 및 분석하여, SOX 법안에서 요구하는 수준의 기업 내부통제를 위한 세션로깅시스템을 제안한다. 본 논문에서 제안하는 시스템은 운영체제에 접속한 사용자의 불법적인 행위를 모니터링하고, 그 행위 과정의 세부 로그를 통해 명확한 증거를 제시할 수 있도록 하고 있다. 이를 위해 논문에서 제안한 별도의 여러 서비스를 추가하여 운영체제를 변경하는데, 이러한 서비스는 기존의 운영체제가 제공하는 인터페이스를 이용하면서 접근을 제어하고 로그를 획득하기 위한 기능을 추가적으로 제공한다. 서버에 접속한 관리자 및 사용자의 행위에 대한 세션 로그를 중앙 집중적으로 저장, 관리하고 해당 로그에 대한 검색 및 조회 기능을 제공할 수 있도록 하여, SOX 법안에서 요구하는 수준의 기업 내부통제를 위한 컴퓨터 포렌식 시스템 및 로그 기술을 제안한다.

• 한국대기환경학회지
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• 제20권3호
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• pp.281-290
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• 2004

The main purpose of this study was to characterize the air pollutants emission factors in electric power plant (EPP) using fossil fuels. The electric power plant is a major air pollution source, thus knowing the emission characteristics of electric power plant is very important to develop a control strategy. The major air pollutants of concern from EPP slacks are particulate matter (PM), sulfur oxides (SOx), nitrogen oxides (NOx), carbon monoxide (CO) and heavy metals. Throughout the study, the following results are estimated - PM : 8.671E-05 ∼ 8.724E+01 PM emission (kg) per fuel burned (ton) - SOx : 4.149E-04∼7.877E+01 SOx emission (kg) per fuel burned (ton) - NOx 1.578E-02∼9.857E+00 NOx emission (kg) per fuel burned (ton) - CO : 3.800E-04∼1.291E+00 CO emission (kg) per fuel burned (ton) - Hg : 1.220E+01∼3.108E+02 Hg emission (mg) per fuel burned(ton) From the statistical analysis by Wilcoxon signed ranks test between the emission factors of ours and U.S. EPA's, we can yielded that : p 〉0.05.

• 한국대기환경학회지
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• 제27권6호
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• pp.672-680
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• 2011

Three new granular absorbents were prepared from calcium hydroxide, and applied to an FGD process with internal circulation. The aim of the study was finding the most efficient of the these three applied absorbents for the $SO_2$ removal at high flue gas temperatures. The absorbent is fed to the testing unit at high operation temperature and fluidized inside the FGD system where the sorbent particles react with the $SO_2$ gas. The rate of $SO_2$ decomposition was high in C-type absorbent which had the large surface area. De-SOx characteristics of the current absorbents appeared to be similar to the other conventional agents in this fluidized bed combustor. In particular, the optimum de-SOx condition could be achieved at high mole ratios of Ca to S which can reduce the residual $SO_2$.

• 자원리싸이클링
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• 제29권1호
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• pp.62-69
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• 2020

산업단지 내 입주기업들의 제조공정에서는 미세먼지 생성 원인물질인 질산화물(NOx), 황산화물(SOx), 휘발성 유기화합물(VOCs) 등이 다양한 형태로 배출되고 있다. 본 연구에서는 효과적인 산업단지 미세먼지 저감을 위해 산재해 있는 공공데이터를 활용하여 산업단지별 특성을 분석하고 미세먼지 감축 기술과 매칭하여 미세먼지를 감축할 수 있는 최적화 감축 방안을 제시하였다. 데이터를 기반으로 한 산업단지 별 맞춤형 기술 및 설비 적용은 미세먼지 전구물질을 공정에서 사전에 감축함으로써 산업단지 미세먼지 뿐만 아니라 제조업 미세먼지 감축을 위한 효과적인 대안이 될 것이다.

• International Journal of Oral Biology
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• 제45권4호
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• pp.197-203
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• 2020

Mesenchymal stem cells in the dental pulp exhibit a tendency for differentiation into various dental lineages and hold great potential as a major conduit for regenerative treatment in dentistry. Although they can be readily isolated from teeth, the exact characteristics of these stem cells have not been fully understood so far. When compared to two-dimensional (2D) cultures, three-dimensional (3D) cultures have the advantage of enriching the stem cell population. Hence, 3D-organoid culture and 3D-sphere culture were applied to dental pulp cells in the current study. Although the establishment of the organoid culture proved unsuccessful, the 3D-sphere culture readily initiated the stable generation of cell aggregates, which continued to grow and could be passaged to the second round. Interestingly, a significant increase in SOX2 expression was detected in the 3D-spheroid culture compared to the 2D culture. These results indicate the enrichment of the stemness-high population in the 3D-sphere culture. Thus, 3D-sphere culture may act as a link between the conventional and 3D-organoid cultures and aid in understanding the characteristics of dental pulp stem cells.

• 청정기술
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• 제16권4호
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• pp.254-257
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• 2010

중국 Liaoning에서 산출된 천연 수활석(brucite)을 원료로 $Mg(OH)_2$ slurry를 제조하고, 그 탈황 성능을 조사하였다. 수활석의 입도분포의 차이 및 수열처리에 의한 활성화 효과를 검토하였다. 80 mesh 이하의 수활석 시료에 비해 입자의 크기가 작고 입도분포가 좁은 1000 mesh 이하의 사료가 de-$SO_2$ 효율이 더 높은 것을 확인할 수 있었다. 한편, 80 mesh 이하의 수활석 시료를 비교적 낮은 온도인 363 K에서 3 h 동안 수열 처리하여 매우 높은 de-$SO_2$ 성능 개선 효과를 얻을 수 있었다.

• Animal Bioscience
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• 제36권8호
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• pp.1180-1189
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• 2023

Objective: Discovering the mechanism of cell specification is important to manipulate cellular lineages. To obtain lineage-specific cell lines, the target lineage needs to be promoted, and counterpart lineages should be suppressed. Embryos in the early blastocyst stage possess two different cell populations, the inner cell mass (ICM) and trophectoderm. Then, cells in the ICM segregate into epiblasts (Epi) and primitive endoderm (PrE). PrE cells in embryos show specific expression of platelet-derived growth factor (PDGF) and its receptor, PDGF receptor A (PDGFRA). In this study, we suppressed PDGF signaling using two methods (CRISPR/Cas9 injection and inhibitor treatment) to provide insight into the segregation of embryonic lineages. Methods: CRISPR/Cas9 RNAs were injected into parthenogenetically activated and in vitro fertilized embryos. The PDGF receptor inhibitor AG1296 was treated at 0, 5, 10, and 20 µM concentration. The developmental competence of the embryos and the number of cells expressing marker proteins (SOX2 for ICM and SOX17 for PrE) were measured after the treatments. The expression levels of the marker genes with the inhibitor were examined during embryo development. Results: Microinjection targeting the PDGF receptor (PDGFR) A reduced the number of SOX17-positive cell populations in a subset of day 7 blastocysts (n = 9/12). However, microinjection accompanied diminution of Epi cells in the blastocyst. The PDGF receptor inhibitor AG1296 (5 µM) suppressed SOX17-positive cells without reducing SOX2-positive cells in both parthenogenetic activated and in vitro fertilized embryos. Within the transcriptional target of PDGF signaling, the inhibitor significantly upregulated the Txnip gene in embryos. Conclusion: We identified that PDGF signaling is important to sustain the PrE population in porcine blastocysts. Additionally, treatment with inhibitors was a better method to suppress PrE cells than CRISPR/Cas9 microinjection of anti-PDGF receptor α gene, because microinjection suppressed number of Epi cells. The PDGF receptor might control the number of PrE cells by repressing the proapoptotic gene Txnip. Our results can help to isolate Epi-specific cell lines from blastocysts.

• 환경정보
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• 제6권3호
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• pp.32-36
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• 1984