• 제목/요약/키워드: Optimal Region

검색결과 1,125건 처리시간 0.032초

CT영상에서 개별 치아 분리를 위한 적응 최적 임계화 방안 (Adaptive Optimal Thresholding for the Segmentation of Individual Tooth from CT Images)

  • 허훈;채옥삼
    • 대한전자공학회논문지SP
    • /
    • 제41권3호
    • /
    • pp.163-174
    • /
    • 2004
  • 치과 분야에서는 치아교정이나 수술 시뮬레이션을 위해서 각 치아를 개별적으로 조작할 수 있는 3차원 치아모델이 필요하다. 치아 CT 영상으로부터 이러한 치아모델의 재구성을 위해서는 각 치아를 이웃한 치아나 치조골로부터 정확하게 분리할 수 있어야 한다. 본 연구에서는 치아 영역을 효과적으로 분리하기 위한 영상정규화 방안과 최적임계화방안을 제안한다. 제안된 방법은 연속적인 CT 영상 슬라이스들에서 치아영역의 형태와 밝기는 점진적으로 변한다는 사실을 근거로 이전 슬라이스에서 추정된 임계치를 이용하여 현 슬라이스의 임시치아경계를 결정하고 이것을 바탕으로 보다 정확한 임계치를 계산한다.

Optimal Groundwater Management Model for Coastal Regions Using Parallel Genetic Algorithm

  • Park, Nam Sik;Hong, Sung Hun;Shim, Myung Geun
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2004년도 학술발표회
    • /
    • pp.77-89
    • /
    • 2004
  • A computer model is developed to assess optimal ground water pumping rates and optimal locations of wells in a coastal region. A sharp interface model is used to simulate the freshwater and salt water flows. Drawdown, upconing, saltwater intrusion and the contamination of well are considered in this model. A genetic algorithm with parallel processing is used to identify the optimal solution.

  • PDF

A TRUST REGION METHOD FOR SOLVING THE DECENTRALIZED STATIC OUTPUT FEEDBACK DESIGN PROBLEM

  • MOSTAFA EL-SAYED M.E.
    • Journal of applied mathematics & informatics
    • /
    • 제18권1_2호
    • /
    • pp.1-23
    • /
    • 2005
  • The decentralized static output feedback design problem is considered. A constrained trust region method is developed that solves this optimal control problem when a complete set of state variables is not available. The considered problem is interpreted as a non-linear (non-convex) constrained matrix optimization problem. Then, a decentralized constrained trust region method is developed for this problem class exploiting the diagonal structure of the problem and using inexact computations. Finally, numerical results are given for the proposed method.

예혼합 화염후류에서 열전달이 CO 및 NOx 생성 특성에 미치는 영향 (Effect of Heat Loss on CO and NOx Emission Characteristics in the Postflame Region of Premixed Flames)

  • 김종민;김태현;금성민;김세원;장기현;이창언
    • 한국연소학회지
    • /
    • 제13권4호
    • /
    • pp.1-7
    • /
    • 2008
  • Strict pollutant regulations of NOx emission and increasing awareness of the environmental damage stimulated interest in research to obtain useful information regarding CO and NOx reductions at the same time. In this study, $CH_4$/air premixed flame was examined numerically to reduce CO and NOx emission level simultaneously in the post-flame region by the heat loss models in which radiative and combined conductive and convective heat losses were included. To reduce the NOx emission, first heat exchanger location was decided near the flame. After first heat exchanger was decided for the optimal NOx emission(about 30 ppm), in order to decide the optimal CO emission(about 30ppm), seocond heat exchanger location was tested and decided for several cases. Finally, the optimal location of heat exchanger for minimal CO and NOx emission simultaneously were determined and suggested.

  • PDF

점熔接材 의 破壞擧動 과 應力分布 (A Study on Behavior of Fracture and Stress Distribution in Spot Welds)

  • 송삼홍;김부동
    • 대한기계학회논문집
    • /
    • 제8권3호
    • /
    • pp.224-231
    • /
    • 1984
  • 본 연구에서는 이상과 같은 점을 고려하고, 인장시험을 통해 최대용접강도를 나타내는 최적용접조건을 구한 다음, 최적조건하에서 박강판을 1점 점용접한 재료의 너깃주위에 관찰되는 파괴거동을 광탄성 응력분포거동과 관련시켜 고찰하였다.

과도상태 설계민감도를 이용한 유도가열코일의 최적설계 (Optimal Design of the Induction Heating Coil using Transient Design Sensitivity Analysis)

  • 곽인구;변진규;최경;한송엽
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
    • /
    • 제49권5호
    • /
    • pp.327-337
    • /
    • 2000
  • In this paper, the design sensitivity formula for the control of the transient temperature distribution is developed using the direct differentiation method, and used for the optimal design of induction heating coil position. The temperature distribution is calculated using the heat source of the induced eddy current and heat diffusion equation. The physical property variations of the workpiece depending on the temperature are considered. The eddy current distribution and the temperature distribution are calculated with the 2D finite element procedure. The adjoint variable technique is employed in expressing the design sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region of the sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region sensitivity. The goal of the design is to have the desired distribution of the temperature on a specific region of the workpiece. The numerical example shows that the proposed design sensitivity analysis for the control of the transient temperature distribution is very useful and practical in the optimal design of induction heating coils.

  • PDF

Thermography의 분석방법에 관한 기초연구 (A Basic Study on the Analysis Method of Thermography)

  • 이혁재;박영재;오환섭;이상철;박영배
    • 대한한의진단학회지
    • /
    • 제9권2호
    • /
    • pp.110-122
    • /
    • 2005
  • Background: The basic concept of thermographic interpretation is the thermologic equality of both side in normal person. But both sides diseases were limited diagnostic values by thermographic interpretation, and this interpretation does not apply to the case in thermal temperature of each part of body. Nevertheless, the measurement conditions are not standardized. So, for its clinical applications are extended, we think that the measurement conditions are considered the individual variations. Objectives: The purpose of this study is to examine the optimum conditions thermal temperature of the time period and region are not effected by internal and external variables. Methods: After the subjects took off their clothes, the filming were repeatedly five times made on duration of 5minutes during 20minutes. We selected nine regions around acupoints including Yin dang[印堂, HN1], Sugu[水溝, GV26], Ch’ondol[天突, CV22], Chonjung[CV17], Chung-wan[中脘, CV12], Ch’onch'u[天樞 S25], No-gung[勞宮, P8], and calculated based on the utility of R.O.I.(Region of Integer) in our system these points temperature. We measured the optimal time period and region that has little variation of thermal temperature. Results: The results shows that the optimal time period is 20minutes after undressed, and the optimal region is the region around acupoints including Sugu[水溝, GV26]. Conclusions: we obtained the measurement conditions were considered the individual variations. And also, this study offers basic sources for that the measurement conditions would be standardized. Furthermore, based on this results, we expect that clinical applications using thermography would be extended.

  • PDF

최대유통문제에서의 매개변수계획법 (The Paramatric Analysis in Maximum Flow Problem)

  • 정호연
    • 산업경영시스템학회지
    • /
    • 제20권44호
    • /
    • pp.81-92
    • /
    • 1997
  • The purpose of this paper is to develop a method of paramatric analysis that can be applied to an optimal solution of a maximum flow problem. We first define the transformed network corresponding to a given network. In such a network, we conduct paramatric analysis by determining changes in the optimal solution precipitated by changes in the capacity as the arc capacity varies from 0 to infinite. By this method we can easily calculate not only the characteristic region where the given optimal solution remains unchanged, but also the characteristic region where the value of the maximal flow gradually increases or decreases. The proposed method is demonstrated by numerical example.

  • PDF

최대유통문제의 사후분석 (Postoptimality Analysis of the Maximum Flow Problem)

  • 정호연;안재근;박순달
    • 대한산업공학회지
    • /
    • 제23권4호
    • /
    • pp.825-833
    • /
    • 1997
  • The purpose of this paper is to develop a method of postoptimality analysis that can be applied to an optimal solution of a maximum flow problem. We first use the transformed network corresponding to a given network. In such a network we conduct postoptimality analysis by determining changes in the optimal solution precipitated by changes in the capacity as the arc capacity varies from 0 to infinite. By this method we can easily calculate not only the characteristic region where the given optimal solution remains unchanged, but also the characteristic region where the value of the maximal flow gradually increases or decreases. The proposed method is demonstrated by numerical example.

  • PDF

채터없는 안정 가공을 위한 자기베어링 밀링 주축의 PID 제어 게인 튜닝 연구 (A study on the PID controller-gain tuning of the magnetically suspended milling spindle for chatter-free cutting)

  • 경진호;노승국;박종권;박선원
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2003년도 춘계학술대회 논문집
    • /
    • pp.117-120
    • /
    • 2003
  • A method for PID controller tuning based on process models for unstable processes was introduced. The optimal. proportional and derivative gains of the AMBs were determined by the tuning method and utilized for the chatter stability analysis in order to search for the chatter-free cutting region. The stability analysis results showed that the optimal gains give wider chatter-free cutting region, and as a result the proposed tuning method was confirmed to be an effective tuning method for determining the optimal gains of the AMBs.

  • PDF