• 제목/요약/키워드: scale down

검색결과 840건 처리시간 0.03초

Scale-down 된 Polyestrene 박막 안에 분산된 InP 나노입자를 사용하여 제작한 비휘발성 메모리 저장용량 특성

  • 이세한;서가;김태환
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
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    • pp.417-417
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    • 2012
  • 나노복합체를 이용하여 제작한 유기 쌍안정성 형태의 비휘발성 메모리 소자는 간단한 공정과 플렉서블 기기에 응용 가능성 때문에 많은 연구가 진행되고 있다. 나노복합체를 사용하여 제작한 비휘발성 메모리 소자의 전기적 성질에 대한 연구는 많이 진행되었으나, Scale-dwon 효과를 고려한 연구가 미흡하다. 본 연구에서는 polyestrene (PS) 박막 층 내부에 분산된 InP 나노입자를 사용한 메모리 소자를 제작하여 전기적 특성을 관찰하였다. InP 나노입자를 PS와 용매인 octadecene에 용해한 후에 초음파 교반기를 사용하여 두 물질을 고르게 섞었다. 고도핑된 Si 기판위에 100 nm 두께의 $SiO_2$ 위에 InP 나노입자와 PS가 섞인 용액을 스핀 코팅한 후, 열을 가해 용매를 제거하여 InP 나노입자가 PS에 분산되어 있는 나노복합체 박막을 형성하였다. 형성된 나노복합체 박막 위에 상부 전극으로 Al을 열증착하여 비휘발성 메모리 소자를 제작하였다. 제작된 메모리 소자는 Al 전극을 마스크를 사용하여 플라즈마 에싱 장비로 에칭을 하였다. 에칭된 소자와 에칭하지 않은 소자의 정전용량-전압 특성을 측정하였다. Flat band 이동은 에칭된 소자가 0.3 V이며 에칭하지 않은 소자는 1.3 V이다. 실험 결과는 에칭을 통해 전기장에 영향 받는 영역이 작아지므로 flat band 이동이 줄어들었다. 에칭방법을 통한 scale-down 효과로 정전용량이 줄어드는 것을 알 수 있었다.

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vMOS 기반의 DLC와 MUX를 이용한 용량성 감지회로 (Design of a Capacitive Detection Circuit using MUX and DLC based on a vMOS)

  • 정승민
    • 한국ITS학회 논문지
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    • 제11권4호
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    • pp.63-69
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    • 2012
  • 본 논문에서는 용량성 지문센서의 회색조 이미지를 얻기 위한 새로운 회로를 제안하고 있다. 기존의 회로는 회색조 이미지를 얻기 위해 많은 칩 면적을 차지하는 DAC를 적용하거나 전력소모가 많고 전역 클럭을 적용하는 비휘발성 메모리에 적용되는 승압회로를 픽셀별로 적용하였다. 개선된 전하분할 방식의 용량성 지문센서 감지회로는 뉴런모스(vMOS) 기반의 DLC(down literal circuit) 회로와 단순화된 아날로그 MUX(multiplexor)를 적용하였다. 설계된 감지회로는 0.3V, $0.35{\mu}m$ CMOS공정을 적용하여 동작을 검증하였다. 제안된 회로는 기존의 비교기와 주변회로를 필요로하지 않으므로 단위 픽셀의 레이아웃 면적을 줄이고 이미지의 해상도를 향상 시킬 수 있다.

중유화력발전소 탈황 흡수탑 세정시기예측 (Estimation of Washing Duration of Desulfurized Absorber in a Heavy Oil Power Plant)

  • 장영기;유호선
    • 플랜트 저널
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    • 제12권1호
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    • pp.24-28
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    • 2016
  • 중유를 연소하는 D 발전소 탈황설비는 운전시간의 경과에 따라 흡수탑 내부에 석고 스케일이 부착되어 발전가능 최대출력의 하향조정이 발생되고 나아가 발전정지를 초래한다. 스케일 제거를 위한 탈황설비 세정은 발전가능 최대출력의 하향조정이 발생하는 시점으로 결정할 수 있다. 본 연구에서는 탈황설비의 운전 자료를 분석하여 발전가능 최대출력의 하향조정이 발생되기 6주전은 탈황설비 출구 $SO_2$ 농도값이 130ppm을 초과하고 동시에 흡수탑 차압은 $380mmH_2O$을 초과하며, 직전 흡수탑 세정 이후 44주가 경과된 시점이 됨을 확인하였다. 최종적으로 흡수탑의 세정시기는 직전 세정시점으로부터 50주가 경과된 시점임을 예측하였다.

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메가와트급 부유식 해상풍력발전기용 페어리드 체인 스토퍼의 강도 성능평가를 위한 구조 모형 시험 (Structural Model Test for Strength Performance Evaluation of Fairlead Chain Stopper Installed on MW Class Floating Type Offshore Wind Turbine)

  • 송창용
    • 한국산업융합학회 논문집
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    • 제26권3호
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    • pp.421-431
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    • 2023
  • Recently, the destructive power of typhoons is continuously increasing due to the influence of global warming. In a situation where the installation of floating wind turbines is increasing around the world, concerns about the huge loss and collapse of floating offshore wind turbines due to strong typhoons are deepening. Regarding to the safe operation of the floating offshore wind turbine, the development of a new type of disconnectable mooring system is required. A new fairlead chain stopper considered in this study is devised to more easily attach or detach the floating offshore wind turbine with mooring lines comparing to other disconnectable mooring apparatuses. In order to investigate the structural safety of the initial design of fairlead chain stopper that can be applied to MW-class floating type offshore wind turbine, scale-down structural models were produced using a 3-D printer and structural tests were performed on the models. For the structural tests of the scale-down models, tensile specimens of acrylonitrile butadiene styrene material that was used in the 3-D printing were prepared, and the material properties were evaluated by performing the tensile tests. The finite element analysis of fairlead chain stopper was performed by applying the material properties obtained from the tensile tests and the same load and boundary conditions as in the scale-down model structural tests. Through the finite element analysis, the structural weak parts on the fairlead chain stopper were reviewed. The structural model tests were performed considering the main load conditions of fairlead chain stopper, and the test results were compared to the finite element analysis. Through the results of this study, it was possible to experimentally verify the structural safety of the initial design of fairlead chain stopper. It is also judged that the study results can be usefully used to improve the structural strength of fairlead chain stopper in a detailed design stage.

지연성근육통 예방을 위한 준비운동과 정리운동이 통증과 근활성도에 미치는 효과 (Effects of Warm-up and Cool-down Exercises for Preventing Delayed Onset Muscle Soreness on Pain and Muscle Activation)

  • 오덕원
    • 한국전문물리치료학회지
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    • 제20권1호
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    • pp.28-35
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    • 2013
  • The purpose of this study was to determine the effects of warm-up and cool-down exercises on pain and muscle activation of delayed onset muscle soreness after intense exercise. Delayed onset muscle soreness was caused by the eccentric exercise in the elbow flexor muscle of the non-dominant upper limb. Forty-four subjects volunteered to participate in this study and were randomly assigned to one of the following groups: warm-up and cool-down group, only warm-up group, only cool-down group, or control group with no intervention. The level of perceived pain using the visual analogue scale and electromyographic activation change in maximal voluntary isometric contraction were measured 4 times at the following times: 10 min, 24 hr, 48 hr, and 72 hr after the exercise. The results revealed the main effect between the groups and interaction effect between the group and measurement session (p<.05). The warm-up and cool-down group showed most favorable results with respect to reduced perceived pain level and increased muscle strength in most measurement sessions, and the only warm-up group showed significantly more decreased pain level than the control group at 24 hr and 48 hr and more increased muscle activation than the cool-down group at 48 hr (p<.05). However, there were no significant differences in pain level and muscle activation between the only cool-down group and control group at all measurement sessions (p>.05). The findings suggest that the warm-up exercise performed before an intense exercise had beneficial effects on the symptoms of delayed onset muscle soreness, whereas cool-down exercise performed after the intense exercise did not.

다운증후군 (Down's syndrome)의 한의학적(韓醫學的) 치료(治療)에 관한 고찰(考察) - 중의학(中醫學) 저널을 중심(中心)으로 - (The Literature Study on Treatment of Down's Syndrome - Within Chinese Medical Journal -)

  • 정준석;김기봉
    • 대한한방소아과학회지
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    • 제26권4호
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    • pp.61-70
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    • 2012
  • Objectives: Literature Study of clinical cases with Traditional Chinese Medicine (TCM) as reference for Korean medicine based treatment of juvenile patients with Down's syndrome. Methods: 4 TCM journals with the highest impact factors were searched and selected among the journals listed in www.cnki.net. The search keywords were "蒙古症", "唐氏症(産生唐氏症)", "唐氏症候群", "先天愚型", "伸舌樣痴呆", "21三体綜合徵", "三染色体症", "Down's syndrome", and "Mongolism". Accordingly, searched papers were analyzed. Results: Total 6 studies were selected: RCT(5), case report(1). Among the RCT related studies, 2 studies tested the effect of Electroacupuncture (電鍼), 1 study tested the effect of Electroacupuncture and Pharmacopuncture (藥鍼) treatment together, and 2 studies tested the effect of Electroacupuncture and Herbal Medicines (藥物) co-treatment. In all the studies, the study groups showed significantly improved intelligence quotient (IQ) in comparison with the control groups. The case report showed improvement of cognitive ability and other clinical parameters as a result of Acupuncture (鍼) and Herbal Medicines co-treatment in juvenile patients with Down's syndrome. Conclusions: Clinical studies testing the effect of TCM for the treatment of Down's syndrome have been conducted in small scales, and all the studies showed a certain level of brain function improvement of the patients in the study groups. These results implicate that the methods in Korean medicine can be highly potential treatment options for the treatment of Down's syndrome. Conduction of accurate and well-controlled studies in large scale would be required to prove the effect of Korean medicine for the treatment of patients with Down's syndrome.

발목관절 강화운동이 낙상경험이 있는 노인의 통증, 관절가동범위, 균형능력에 미치는 효과 (The Effect of Ankle Strengthening Exercise who Old Man Have fall Down Experience on Pain, ROM and Balance Ability)

  • 안목
    • 대한물리치료과학회지
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    • 제18권3호
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    • pp.79-86
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    • 2011
  • Background : The purpose of this study was to investigate on the ankle pain, Range of Motion(ROM) and balance ability with old man have fall down experience used to ankle strengthening exercise for 6 weeks. We introduced ankle strengthening exercise in this study in order to recover the pain, ankle ROM and balance ability. Methods : Twenty-four old mans have fall down experience were included for the study. Among them, twelve old mans(experimental group) were ankle strengthening exercise and physical science methods(H/P, TENS, U/S), another twelve old mans(control group) were treated by physical science methods(H/P, TENS, U/S). Each group made use of Visual Analogue Scale(VAS) to pain and goniometer to ankle ROM and Berg Balance Test(BBS) to balance ability to compare the possible changes of pain, ROM and balance ability in two groups after treatment. Results : In experimental group, pain reduced, ankle ROM has increased in dorsi-flexion, plantar-flexion and balance ability has increased for 6 weeks. In control group, pain reduced, ankle ROM has not changed in dorsi-flextion, plantar-flextion and balance ability has not changed for 6 weeks. Conclusion : According to the results, we concluded that ankle strengthening exercise for 6 weeks is effective for reducing pain and increasing ankle ROM and balance ability. Therefore, we thought the old man have fall dawn experience need ankle strengthening exercise for prevention repeatedly fall down.

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곡선 PSC 사장교의 극한해석을 위한 개선된 하중제어법 (An Improved Load Control Strategy for the Ultimate Analysis of Curved Prestressed Concrete Cable-Stayed Bridge)

  • 최규천;이재석
    • 한국전산구조공학회논문집
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    • 제22권1호
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    • pp.1-13
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    • 2009
  • 이 논문에서는 복잡한 기하학적 형상과 비선형 특성들을 보이는 곡선 프리스트레스트 콘크리트(PSC) 사장교의 극한거동을 안정적으로 예측하기 위한 비선형 해법을 제시하였다. PSC 교량 구조물의 비선형 거동 및 극한거동을 예측하기 위한 해법으로서 하중제어법(load control strategy)과 변위제어법(displacement control strategy)을 적용하였다. 콘크리트의 과다한 균열과 재료상태 및 케이블 장력의 급격한 변화로 인해 불평형력(unbalanced load)이 크게 변화하여 이들 두 해법으로 해를 구할 수 없는 경우에 대한 대안으로서 불평형력을 적정한 비율로 감소시키면서 하중제어 법을 적용하여 해를 안정적으로 구해 나가는 불평형력 감쇠(scale-down of the unbalanced load)를 적용한 하중제어법을 제시하였다. PSC 거더교의 극한해석을 수행하여 불평형력 감쇠를 적용한 하중제어법의 정당성을 평가하였다. 또한 곡선 PSC 사장교의 극한해석에 이 논문에서 제시한 비선형 해법을 적용하여 복잡한 비선형성으로 인해 해가 수렴하기 어려운 해석에도 이 해법이 유용함을 확인하였다.

고효율 순산소 버너의 연소 특성에 관한 실험적 연구 (Experimental study on combustion characteristics of high efficiency oxy-fuel burner)

  • 김세원;안재현;김민수
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2002년도 제25회 KOSCI SYMPOSIUM 논문집
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    • pp.57-64
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    • 2002
  • This paper describes the results of a series of experiments executed by using two pilot-scale oxv-fuel burners are designed for maximum capacity of 50,000 kacl/hr, 300,000 kcal/hr and installed in the test furnace. The effects of turn-down ratio, excess oxygen ratio, nozzle exit velocity, injection angle, swirl vane angle and inlet oxygen temperature on the combustion characteristic are investigated. Temperature distributions are measured using R-type and Molybdenum sheathed C-type thermocouple. The results showed that maximum temperature and mean temperature increase with the increase of turn-down ratio and inlet oxygen temperature. The maximum flame temperature was increased about 35% compared to the case of equivalent air operated condition. In addition, Optimum excess oxygen ratio and nozzle characteristics are obtained for this oxy-fuel glass melting furnace.

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