• 제목/요약/키워드: oval weighting

검색결과 4건 처리시간 0.019초

지구(地球)의 잠재자연식생분포(潜在自然植生分布)를 추정(推定)하기 위한 최적구면보간법(最適球面補間法)의 개발(開發) (Development of the Best Spherical Interpolation Method for Estimating Potential Natural Vegetation Distribution of the Globe)

  • 차경수;오치아이 가미야
    • 한국산림과학회지
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    • 제86권1호
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    • pp.17-24
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    • 1997
  • 지구(地球)의 잠재자연식생분포(潛在自然植生分布)를 추정(推定)하기 위한 첫단계로서 자연식생분포(自然植生分布)와 밀접(密接)한 관계가 있는 기온(氣溫)과 강수량(降水量)에 대한 최적구면보간방법(最適球面補間方法)을 개발하기 위해, Light Climatic Dataset로 명명(命名)한 전세계에 분포(分布)된 1,060점의 측후소(測候所)의 실측자료(實測資料)를 보간용(補間用)과 검정용(檢定用)으로 무작위(無作爲) 2등분(等分)하고, 검정용(檢定用) 측후소(測候所)에 있어서 관측치(觀測値)와 보간용(補間用)에 의한 추정치(推定値)와의 오차(誤差)를 보간방법(補間方法)과 파라메타가 틀린 조합(組合)에 대해 상호비교(相互比較)하였다. 보간용(補間用)에 의한 추정치(推定値)는, 측후소(測候所)의 선택법(選擇法)으로 전점(全点), 정점(定点), 안반경(安半徑)의 3가지 방법, 거리에 대한 하중(荷重)으로 n승 반비례(反比例), 부(負)의 지수함수(指數函數)의 2가지 방법, 방위(方位)에 관한 하중(荷重)으로 타원하중법(楕圓荷重法), 각각에대해 상호조합(相互組合)하여 산출(算出)되었다. 그 결과, 측후소(測候所)의 선택법(選擇法)은 정반경법(定半徑法), 거리(距離)에 관한 하중식(荷重式)은 부(負)의 지수함수(指數函數), 방위(方位)에 관한 하중법(荷重法)은 타원하중법(楕圓荷重法)을 조합(組合)하는 것이 기온(氣溫)과 강수량(降水量)의 보간(補間)에 적합(適合)하였으며, 그에 관한 파라메타 값은 기온(氣溫)에 있어서 정반경(定半徑) $30^{\circ}$, -0.78의 지수함수(指數函數), 타원하중(楕圓荷重) 0.4로, 강수량(降水量)에 있어서는 각각 $35^{\circ}$, -0.53, 1.2로 나타났다.

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Prediction Model of the Exit Cross Scetional Shape in Round-Oval -round Pass Rolling

  • Lee, Young seog;Gert Goldhahn
    • International Journal of Precision Engineering and Manufacturing
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    • 제2권1호
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    • pp.87-93
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    • 2001
  • A reliable analytic model that determines the exit cross sectional shape a workpiece(material) in round-oval (oroval-round) pass sequence has been developed. The exit cross sectional shape of an outgoing workpiece is predicted by using the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groovw to the roll axis direction. The requirements placed on the choice of the weighting function were to ensure boundary conditions specified. The validity of the analytic model has been examined by not rod rolling experiment with the roll gap and specimen size changed. The exit cross sectional shape and area of the workpiece predicted by the proposed analytic model were good agreement with those obtained experimentally. We found that the analytic model has not only simplicity and accuracy for practical usage but also save a large amount of computational time compared with finite element method.

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선재압연공정의 소재 자유표면 형상예측 (Prediction of Stress Free Surface Profile of Wrokpiece in Rod Rolling Process)

  • 이영석;김영호;진영은
    • 한국정밀공학회지
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    • 제17권9호
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    • pp.174-180
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    • 2000
  • A reliable analytic model that determines the cross sectional shape of a workpiece(material) in round-oval(or oval-round) pass sequence has been developed. the cross sectional shape of an outgoing workpiece is predicted by using the linear interpolation of the radius of curvature of an incoming workpiece and that of roll groove to the roll axis direction. The requirements we placed on the choice of the weighting function were to ensure boundary conditions specified. The validity of the analytic model has been examined by hot rod rolling experiment with the roll gap and specimen size changed. The cross sectional shape and area of a workpiece predicted by the proposed analytic model were good agreement with those obtained experimentally. It was found that the analytic model has not only simplicity and accuracy for practical usage but also save a large amount of computational time compared with finite element method.

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말티즈 견의 두개골에서 발생한 다엽성 종양 (Multilobular Tumor of Skull in a Maltese Dog)

  • 양철호;강민희;김승곤
    • 한국임상수의학회지
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    • 제33권1호
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    • pp.48-50
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    • 2016
  • A 10-year-old spayed female Maltese dog weighting 3.4 kg was referred with growing firm mass at the parietal bone region from 2 weeks ago. A firm, partially calcified mass ($1.9cm{\times}4.4cm$) was palpated in the region of the frontal and parietal skulls but had no neurologic signs. Computed tomography (CT) characteristics of mass were round to oval shape, fine granular appearance, and well defined margins. Mass involving the calvarial bones had invasion into the cranial vault with a significant intracranial portion. Histologically, the tumor was characterized by the presence of multiple lobules containing osteoid or cartilage in the center that were separated by anastomosing fibrous septae. This is case report described the clinical and histopathological features of multilobular tumor of skull in a Maltese dog.