• 한국산학기술학회논문지
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• 제11권3호
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• pp.1066-1070
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• 2010

본 연구는 2008년 1월부터 2008년 12월까지 S 유치원 원아40명(실험군 20명, 대조군 20명)의 뇌파를 검사 하여 뉴로피드백 훈련 전과 훈련 후의 스트레스 저항 능력을 보고자 하였다. 훈련 전과 후의 스트레스 저항능력은 시계열 선형분석을 통하여 비교하였으며, 연구의 결과로 뉴로피드백 훈련을 적용한 집단에서 항 스트레스 지수에서 유의미한 차이를 보였다. 이 결과는 뉴로피드백 훈련이 유아들의 스트레스 저항 능력을 높여 주었으며 정서적 성향에 긍정적인 영향을 미쳤다고 본다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.790-793
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• 2005

In these days, the piezoresistive material has been applied to various sensors in order to measure the change of physical quantities. But the relationship between the sensitivity of a sensor and the position and size of piezoresistor has rarely been studied. Therefore, this paper was focused on the effect of residual stress induced in piezoresistor on the distribution of resistance change ratio and supposed the feasible position of piezoresistor. The resulting are following; The tensile residual stress in the vicinity of piezoresistor decreased the value of resistance change ratio and could not effect on all the area of diaphragm but local area around the piezoresistor. Also, the piezoresistor in the diaphragm type pressure sensor with boss should fabricate in the edge of boss in order to increase the sensitivity of pressure sensor.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1996년도 토목섬유(Geosymthetics) 학술발표회 논문집
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• pp.67-78
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• 1996

• Journal of Ginseng Research
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• 제45권2호
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• pp.218-227
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• 2021

Background: Panax ginseng is one of the most important medicinal plants and is usually harvested after 5 to 6 years of cultivation in Korea. Heavy metal (HM) exposure is a type of abiotic stress that can induce oxidative stress and decrease the quality of the ginseng crop. Siderophore-producing rhizobacteria (SPR) may be capable of bioremediating HM contamination. Methods: Several isolates from ginseng rhizosphere were evaluated by in vitro screening of their plant growth-promoting traits and HM resistance. Subsequently, in planta (pot tests) and in vitro (medium tests) were designed to investigate the SPR ability to reduce oxidative stress and enhance HM resistance in P. ginseng inoculated with the SPR candidate. Results: In vitro tests revealed that the siderophore-producing Mesorhizobium panacihumi DCY119^T had higher HM resistance than the other tested isolates and was selected as the SPR candidate. In the planta experiments, 2-year-old ginseng seedlings exposed to 25 mL (500 mM) Fe solution had lower biomass and higher reactive oxygen species level than control seedlings. In contrast, seedlings treated with 10⁸ CFU/mL DCY119^T for 10 minutes had higher biomass and higher levels of antioxidant genes and nonenzymatic antioxidant chemicals than untreated seedlings. When Fe concentration in the medium was increased, DCY119^T can produce siderophores and scavenge reactive oxygen species to reduce Fe toxicity in addition to providing indole-3-acetic acid to promote seedling growth, thereby conferring inoculated ginseng with HM resistance. Conclusions: It was confirmed that SPR DCY119^T can potentially be used for bioremediation of HM contamination.

• 한국산학기술학회논문지
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• 제11권9호
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• pp.3318-3324
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• 2010

본 연구는 2008년 3월부터 2009년 2월까지 S시 M동에 위치한 A청각장애인학교 학생 16명(초등학생 6명, 중학생 10명)을 대상으로 일상적 스트레스저항 능력에 뉴로피드백 훈련이 미치는 영향을 보고자하였다. 뇌파 측정 후 뉴로소프트에 포함되어 있는 그림 색칠하기로 휴식, 주의력, 집중력을 각기 1분씩 측정하여 자기조절능력을 분석하였다. 피검자가 피드백한 뇌파 중 상대적 비율이 가장 적은 주파수가 피검자의 훈련모드가 된다. 훈련장소는 A청 각장애인학교 훈련실, 1회 훈련시간은 40분이었으며 일 주일에 최소 2회로 방학을 제외한 8개월 정도 훈련을 실시하였다. 뉴로피드백 훈련 전과 훈련 후의 항스트레스지수, 긴장도(육체적 스트레스), 산만도(정신적 스트레스)의 비교는 뇌파측정을 통한 정량적인 뇌기능분석을 적용하였다. 첫째, 청각장애학생들의 스트레스저항 능력에 뉴로피드백 훈련이 긍정적인 영향을 미쳤으며, 항스트레스(좌 우)가 통계적으로 유의하였다. 둘째, 청각장애학생들의 육체적 정신적 긴장 저항 능력에 뉴로피드백 훈련이 긍정적인 영향을 미쳤으며, 긴장도(좌 우)와 산만도(좌 우)가 통계적으로 유의하였다. 이상의 연구 결과를 종합해 볼 때 청각장애학생들의 일상적 스트레스 저항 능력에 뉴로피드백 훈련이 효과적인 중재임이 검증되었다.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.101.1-101
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• 2003

Lipopolysaccharide, siderophore, and cyclic dipeptide have been shown to be necessary for ISR induction by pseudomnads. However, there is no report on cloning of genes or generating specific mutants involving in ISR activity. A biological control bacteium P. chlororaphis O6 induces resistance to Erwinia carotovora subsp. carotovara SCCI in tobacco and induces drought resistance in Arabidopsis. To isolate genes involved in ISR activity and induction of drough resistance of O6, we constructed Tn5 mutants and were used to screen for ISR activity and drought resistance activity using microtiter assay with tobacco and Arabidopsis. Thirty-three ISR-deficient mutants were selected, and the nine ISR-deficient mutants were also lost activity of drought resistance. The flanking sequence analysis of the ISR and drought resistance-deficient mutants showed that a gacS gene encoding a two-component sensor kinase, and a mce gene encoding a protein involved in mycobacterial cell entry were mutated. The flanking sequence of each Tn5 mutant altered ISR activity is currently under investigation. These results indicate that gacS and mce are important genes in induction of ISR activity and drought resistance of P. chlororaphis O6. Our works will open opportunities for identification of bacterial genes or traits that are involved in ISR activity and induced drought resistance of P. chlororaphis O6.

• 한국강구조학회 논문집
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• 제27권4호
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• pp.387-397
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• 2015

국내의 내화성능평가는 대부분 사양적설계 방법인 품질시험을 통해 이뤄지고 있다. 하지만 시험 특성상 많은 비용과 시간을 요구하며 다양한 건축구조에 대한 내화성능평가에는 어려움이 많다. 따라서 본연구에서는 성능적 설계를 위한 연구로 유한요소 구조해석 프로그램인 ABAQUS를 사용해 H형강 휨재를 대상으로 변수에 따른 열응력 해석을 통해 내화성능을 검토하며, 하중비별 한계온도를 제안한다.

• Corrosion Science and Technology
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• 제3권4호
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• pp.154-160
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• 2004

The Sulfide Stress Corrosion Cracking (SSCC) resistance of structural steels is one of the critical concerns for the operators, material designers, and fabricators of oil-field equipment, especially treating sour gas (H2S) containing fluids. As far as its fabricators concerned, the systematic care of welding parameters should be taken to obtain comparable SSCC resistance of their weldment to that of its base material. In this respect, every different type of welding joint design for this use should be verified to be SSCC-proof with relevant test procedures. In this study, the welding parameters to secure a proper SSCC resistance of steel pipe's weldments were reviewed on the Welding Procedure Qualification Records (WPQR), which had been employed for actual fabrication of an offshore structure for oil and gas production. Based on this review, a guideline of welding parameters, such as, heat input, welding consumable for Y.S. 65 ksi class steel pipe material is proposed in terms of the NACE criteria for SSCC resistance.

• Computers and Concrete
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• 제31권6호
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• pp.469-484
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• 2023

The response mechanism of simply supported two-way reinforced concrete (RC) slabs under fire was numerically studied from the view of stress redistribution using the finite element software ABAQUS. Results show that: (1) Simply supported two-way RC slabs undergo intense stress redistribution, and their responses show four stages, namely elastic, elastic-plastic, plastic and tensile membrane stages. There is no cracking in the fire area of the slabs until the tensile membrane stage. (2) The inverted arch effect and tensile membrane effect improve the fire resistance of the two-way slabs. When the deflection is L/20, the slab is in an inverted arch effect state, and the slab still has a good deflection reserve. The deformation rate of the slab in the tensile membrane stage is smaller than that in the elastic-plastic and plastic stages. (3) Fire resistance of square slabs is better than that of rectangular slabs. Besides, increasing the reinforcement ratio or slab thickness improves the fire resistance of the slabs. However, an increase of cover thickness has little effect on the fire resistance of two-way slabs. (4) Compared with one-way slabs, the time for two-way slabs to enter the plastic and tensile cracking stage is postponed, and the deformation rate in the plastic and tensile cracking stage is also slowed down. (5) The simply supported two-way RC slabs can satisfy with the requirements of a class I fire resistance rating of 90 min without additional fire protection.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2008년도 추계학술대회 논문집
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• pp.134-137
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• 2008

The effects of residual stress and surface defects on the mechanical properties of the high carbon steel filament used for the automotive tire have been experimentally investigated. The samples were fabricated with annealing temperature. The residual stress was measured by focused ion beam and strain mapping software which has advantages, such as data with high accuracy and fast data acquisition time. Mechanical properties, such as tensile strength and fatigue resistance, were gradually increased up to $200^{\circ}C$ and then slightly decreased. From the measurement of residual stress and level of surface defect, it was revealed that the critical factor was varied with different temperature region. That is, the fatigue resistance increased due to decreasing the residual stress and decreased due to increasing the size and distribution of surface defect.