• 제목/요약/키워드: 안대

검색결과 321건 처리시간 0.023초

전력계통 안정을 위한 공급예비력 적정수준에 대한 연구 (A research of optimum supply reserve levels for stability of power system)

  • 안대훈;권석기;주행로;신중선
    • 한국조명전기설비학회:학술대회논문집
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    • 한국조명전기설비학회 2008년도 춘계학술대회 논문집
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    • pp.61-65
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    • 2008
  • Because of the high increasing rate of load demand, these days the necessity of deciding what optimum reserve level is appropriate to most stably supply electricity is being emphasized. This research studies the downward tendency of reverve ratio by analyzing the trend of change of the network scale, reserve, and reserve ratio while optimum reserve has been increased as the network system scale grow up. This means, at this moment 6,000MW is optimum level for short term prospect of power supply and demand. And also, it has been analyzed that, as the annual peak load exceeded 50,000MW, confirming the amount of optimum reserve level is more stable than keeping 10 to 12% reserve ratio.

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Zoogloea ramigera에 의한 생물고분자 생산에 관한 연구 (The Production of Biopolymer by Zoogloea ramigera)

  • 안대희;권해수정윤철
    • KSBB Journal
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    • 제7권3호
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    • pp.166-171
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    • 1992
  • 생물응집체 개발을 목적으로 Zoogloea ramigera115를 이용하여 균주배양 및 생물고분다 생성실험을 시시하였다. 다당류 최고 생성률을 얻을 수 있는 최적기질로 탄소원으로는 glucose, 질소원으로는 $NaNO_3$ 유기영양원으로는 yeast extract가 선택되었다. 초기 pH가 6일 때 가장 높은 세포성장과 점성을 나타내었다. 생성돈 생물고분자는 ultrasonication과 고속 원심분리를 거친 후 propanol 첨가에 의해 효율적으로 추출되었다. 생물고분자는 jae test에 의한 응집실험에서 높은 침강성을 보여 응집제 사용가능성을 확인하였다.

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회전관성과 전단변형을 고려한 수평 곡선보의 자유진동 (Free Vibrations of Horizontally Curved Beams with Rotatory Inertia and Shear Deformation)

  • 이병구;모정만;이태은;안대순
    • 한국소음진동공학회논문집
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    • 제13권1호
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    • pp.63-69
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    • 2003
  • The ordinary differential equations governing free vibrations of elastic horizontally curved beams are derived, in which the effects of rotatory inertia and shear deformation as well as the effects of both vertical and torsional inertias are included. Frequencies and mode shapes are computed numerically for parabolic curved beams with the hinged-hinged, hinged-clamped and clamped-clamped ends. Comparisons of natural frequencies between this study and ADINA are made to validate the theories and numerical methods developed herein. The lowest three natural frequency parameters are reported. with and without the effects of rotatory inertia and shear deformation. as functions of the three non-dimensional system parameters: the horizontal rise to span length ratio. the slenderness ratio and the stiffness parameter.

척추질환으로 인한 통증환자의 최면치료 1례 보고 (A Case Study of Pain Disorder Treated by Hypnosis)

  • 김자영;안대종;이지영
    • 동의신경정신과학회지
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    • 제18권2호
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    • pp.153-162
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    • 2007
  • This study is designed to assess the effect of hypnosis on the pain disorder patient. We treated a patient by using hypnosis as well as traditional oriental therapy-acupuncture, herbal medicine, Chu-Na therapy. We divide the pain into four parts and then we checked the intensities of them comparing with those of the first treatment. The pain worsened by psychic factor was decreased after treatment. Especially, after hypnosis, the intensity of the pain is highly changed. Psychotherapy in oriental medicine can be helpful to treat patients who have psychic and physical disorders.

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자유진동 해석에서 수치미분의 응용 (Application of Numerical Differentiations in Free Vibration Analysis)

  • 이병구;안대순;강희종;김권식
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.814-818
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    • 2003
  • This paper deals with the application of numerical differentiation in free vibration analysis. In the free vibration analysis, the derivative values of the given function are certainly used in calculation of structural parameters. For deriving the derivative values, both the time and labor are needed when the structures consist of non-linear geometries such as arches or curved beams. From this viewpoint, the numerical differentiation scheme is applied into the free vibration analysis. The numerical results obtained from the numerical differentiations are agreed very well with those obtained from the exact derivatives by analytical method. It is expected that the numerical differentiations can be utilized practically in the free vibration analysis.

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자중에 의한 정적 처짐을 고려한 변단면 보의 자유진동 (Free Vibrations of Tapered Beams with Static Deflection due to Self-Weight)

  • 이병구;이태은;안대순;김영일
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 춘계학술대회논문집
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    • pp.423-428
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    • 2002
  • A numerical method is presented to obtain natural frequencies and mode shapes of tapered beams with static deflections due to self-weight. The differential equation governing the free vibrations of beam taken into account the static deflection due to self-weight is derived and solved numerically. The hinged-hinged, clamped-clamped and clamped-hinged and clamped-free end constraints are applied in the numerical examples. As the numerical results, the lowest three natural frequencies versus distributed slenderness ratio and section ratio are reported in figures. And for the comparison purpose, the typical mode shapes with the effects of static deflection are presented in figures.

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한국산 바질(Ocimum basilicum L.)의 휘발성 성분 (Volatile Components of Basil(Ocimum basilicum L.) cultivated in Korea)

  • 안대진
    • 한국식품영양학회지
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    • 제12권5호
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    • pp.513-517
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    • 1999
  • Theessential oils of anise darkopal lettuce and sweet basils cultivated in Korea were extracted by simulatneous steam distillation and extraction method and were analyzed by GC/MSD. Total 41 com-ponents were identified in essential oils including 11 alcohols, 6 carbonyls 19 hydrocarbons and 5 esters components. The major components were 1,8-cineole linalool $\alpha$-bergamotene $\beta$-elemene methyl chavicol, $\beta$-cubebene methyl cinnamate and eugenol. Darkopal lettuce and sweet basils were rich in linalool(30.1-36.5%) methyl chavicol(8.1-25.5%) and relatively poor in methyl cinnamate(0-2.71%) Anise basil was rich in linalool(28.5%) and methyl cinnamate(23.1%) However methyl chavicol which was known as one of the main components of bisil was not detected.

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화학기계적연마(CMP) 컨디셔닝에 관한 연구 (A Study on Novel Conditioning for CMP)

  • 이성훈;김형재;안대균;정해도
    • 한국정밀공학회지
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    • 제16권5호통권98호
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    • pp.40-47
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    • 1999
  • In CMP for semiconductor wafer films, the acceptable within-chip planarity, within-wafer and wafer-to-wafer nonuniformity could be achieved by conditioning. The role of conditioning is to remove continuously polishing residues from pad and to maintain the initial pad surface pores. To reach these requirements, the diamond grits disk has been considered as a conventional conditioner. However, we have investigated many defects as scratch on wafers out of diamond grits shedding, contaminations from bonding materials, and pad pore subsidences by over-conditioning. So, this paper studies the effect of ultrasonic vibration in CMP conditioning as a representative. The effect of ultrasonic vibration was certified through ILD, Metal CMP.

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지하철 개착구 굴착시 주변자반과 구조물에 대한 거동예측과 실측의비교평가 (The Study on the Prediction and Measurement for the Behaviour of Structures and Weathered Soil & Rock in Excavating the Ventilation Shaft)

  • 김융태;안대영;김득기;한창헌
    • 터널과지하공간
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    • 제4권1호
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    • pp.63-76
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    • 1994
  • This paper discusses contents of the existing design, the behaviours prediction on the strut and retaining wall around subsurfaces, and also evaluates the measured results in comparison with the management criterion during excavation period of ventilation shaft at Pusan-Subway 220. Field measurements showed that maximum displacement 23.74 mm at boundary site of multistratification and the weathered rock to be formed at 0.2~0.6 H of total excavating depth(H), 68 ton of maximum axial force and 4.4X102 kg/cm2 of stress on strut. The measured axial force exceeds prediction levels by up to 50 percent at the weathered soil & rock, and the others come under the category of their levels. The great gap of both field measurements and prediction on behaviour makes a difference of the site situation at the design stage and the practical working. This measured value is greatly safety in comparison with that of the safety criterion, but axial force at 4~5 strut of ventilation shaft l is higher than the prediction.

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RP part 표면정도 향상을 위한 후처리 공정 개발 -왁스 코팅과 연삭 후처리 공정 이용- (Development of Post-process for Improving the Surface Roughness of Stereolithography parts - Using Wax Coating and Grinding Post-process -)

  • 안대건;김호찬;최홍태;이석희
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2002년도 추계학술대회 논문집
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    • pp.659-662
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    • 2002
  • SL(Stereolithography) part is made by piling up thin layers which causes the stair stepping effect at the surface of SL parts. This effect brings about excessive surface roughness and requires additional post-process finishing such as abrasive techniques that are detrimental to part geometry and time consuming. Hence a wax coating and grinding post-process is proposed to improve the surface quality of SL part. The wax that has suitable properties for the proposed post-process is coated all over the part surface. By grinding the thin layer of coated on the SL part only, the surface roughness can be improved without any damage on the part. From the experimental results, This approach is considered to be very practical fur die casting with RT(Rapid Tooling) techniques.

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