• 제목/요약/키워드: separating point

검색결과 111건 처리시간 0.021초

ACCURATE SYNTHESIS OF SEEDLING SEPARATING-PLANTING MECHANISM OF RICE TRANSPLANTER

  • Hu, Hanxiang;Chen, Dejun;Wang, Changbing;Li, Zhenyong;Wu, Jienian;Xu, Jinda
    • 한국농업기계학회:학술대회논문집
    • /
    • 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
    • /
    • pp.284-290
    • /
    • 1993
  • In order to improve the adaptability of rice transplanter to seeding with different length when transplanting multicropping rice in south China. The seedling separating planting mechanism is resynthesized in the paper. According to the agronomy requirements of seedling's transplanting, optimum motional path of the tip point of planting needle is obtained. by applying the established kinematic model of the separating planting mechanism, the relevant software is compiled. On the basis of the features of the problem, the constrained optimization method is utilized to solve the problem with 24 restrictions. Thus, the optimum structure parameters are obtained to satisfy the path points accurately.

  • PDF

박리 유선의 곡률 변화가 축대칭 후향계단 흐름에 미치는 영향 (Effect of the separating streamline curvature on the axisymmetric backward-facing step flow)

  • 김경천;부정숙;정지융;양종필
    • 대한기계학회논문집B
    • /
    • 제20권4호
    • /
    • pp.1510-1520
    • /
    • 1996
  • An experimental study on the flow over the axisymmetric backward-facing step was carried out. The purpose of the present study is to investigate the effect of the separating streamline curvature on the reattachment length and to understand the structure of recirculating flows. Local mean and fluctuating velocity components were measured in the separating and reattaching axisymmetric region of turbulent boundary layer on the wall of convex cylinder placed in a water tunnel by using 2-color 4-beam fiber optics laser Doppler velocimetry. The study demonstrates that the reattachment length increases with increasing separating streamline curvature. It is also observed that the reverse flow velocity and turbulent kinetic energy increase with an increase in the separating streamline curvature. In addition, the behavior of maximum turbulent stresses show that the effect of separating streamline curvature is larger in the region of recirculating zone(X/H<2) than in the region of reattachment point.

직접압연공정의 특성해석 및 공정변수 선정 (Characteristic Analysis and Selection of Process Parameters in Direct Rolling Processes)

  • 박영준;조형석;이원호;강태욱
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1997년도 춘계학술대회 논문집
    • /
    • pp.384-388
    • /
    • 1997
  • Recently,direct rolling process has been drawing increasing interests because production cost be greatly reduced by eliminating subsequent hot rolling processes. Such a process has been characterized to prosuce thin steel strip (thickness 1~5mm) directly from molten metal and to skip over the conventional hot rolling processes. However, since there are several process parameters, which affect the quality of product,and their relationship between the parametersare very complex,it is therefore very difficult to realize the process design and the quality control. To overcome these difficulties quantitative relationship between the parameters are investigated through a numerical analysis. Form these results, it is found that solidification final point is the most important paramter which is critical to quality of the strip. Also,the multiple regression model is obtianed to determine their relationship from the solidification final point and roll separating force which can be easily estimated

  • PDF

박리전단층이 축대칭 하향단흐름에 미치는 영향 (Effect Of The Separating Shear Layer on the Flow Over an Axisymmetric Backward-Facing Step)

  • 부정숙;김경천;양종필
    • 대한기계학회논문집
    • /
    • 제19권4호
    • /
    • pp.1102-1115
    • /
    • 1995
  • An experimental study on the flow over the axisymmetric backward-facing step was carried out. The purpose of the present study is to investigate the effect of the boundary layer thickness at the separation point on the reattachment length and to understand the structure of the recirculating flows. Local mean and fluctuating velocity components were measured in the separating and reattaching axisymmetric turbulent boundary layer over the wall of convex cylinder placed in a water tunnel by using 2-color 4-beam fiber optics laser Doppler velocimetry. The study demonstrated that the reattachment length increases with increasing boundary layer thickness. It was also observed that the reverse flow velocity and turbulent kinetic energy decrease with an increase in the momentum thickness at the separation point. The measured velocity field suggests that the boundary layer thickness at the separation can affect definitely on the formation of corner eddy.

CHARACTERIZATIONS OF (JORDAN) DERIVATIONS ON BANACH ALGEBRAS WITH LOCAL ACTIONS

  • Jiankui Li;Shan Li;Kaijia Luo
    • 대한수학회논문집
    • /
    • 제38권2호
    • /
    • pp.469-485
    • /
    • 2023
  • Let 𝓐 be a unital Banach *-algebra and 𝓜 be a unital *-𝓐-bimodule. If W is a left separating point of 𝓜, we show that every *-derivable mapping at W is a Jordan derivation, and every *-left derivable mapping at W is a Jordan left derivation under the condition W𝓐 = 𝓐W. Moreover we give a complete description of linear mappings 𝛿 and 𝜏 from 𝓐 into 𝓜 satisfying 𝛿(A)B* + A𝜏(B)* = 0 for any A, B ∈ 𝓐 with AB* = 0 or 𝛿(A)◦B* + A◦𝜏(B)* = 0 for any A, B ∈ 𝓐 with A◦B* = 0, where A◦B = AB + BA is the Jordan product.

UAM 환경에서의 3D Point Cloud Data 지면/객체 분리 기법 연구 (A Study on Ground and Object Separation Techniques Utilizing 3D Point Cloud Data in Urban Air Mobility (UAM) Environments)

  • 구본수;최인호;유재림
    • 한국항행학회논문지
    • /
    • 제27권4호
    • /
    • pp.481-487
    • /
    • 2023
  • 최근 UAM(Urban Air Mobility)에 대한 관심이 도시의 교통 혼잡과 대기오염 문제 해결 방안으로 급증하고 있다. 하지만 UAM의 효율적인 운영을 위해서는 3D Point Cloud 데이터의 정확한 처리가 필요하며, 특히 지면과 객체를 분리하는 문제가 중요하다. 본 논문은 UAM 환경의 동적이고 복잡한 특성을 고려하여 지면과 객체를 효과적으로 분리하는 방법을 제안하고 검증한다. 우리의 접근 방식은 MEMS 센서로부터 얻은 자세 정보와 RANSAC을 이용한 지면 평면 추정을 결합하여, GPS 오차에 크게 영향 받지 않는 지면/객체 분리를 가능하게 한다. 시뮬레이션 결과는 이 방법이 UAM 환경에서 효과적으로 작동함을 보여주며, 도심 항공 모빌리티의 안전성과 효율성을 향상시키는 중요한 단계를 제시한다. 향후 연구는 이 알고리즘의 정확성을 높이고 다양한 UAM 환경에서 성능을 평가하며, 실제 드론 테스트를 진행할 예정이다.

DSP를 이용한 음성인식기 구현 (Implementation of Speech Recognizer using DSP(Digital Signal Processor))

  • 임창환;문철홍;전경남
    • 대한전자공학회:학술대회논문집
    • /
    • 대한전자공학회 2000년도 추계종합학술대회 논문집(4)
    • /
    • pp.187-190
    • /
    • 2000
  • In this paper, implementation of speech Recognizer system, Separated from Personal computer. By using DSP, this intends to extend the voice recognizing, limited into PC because of amount of data and calculations. For this performance The thesis uses the real time End point detector and organizes no additional device between human and the system, characteristic vector are that detects End point and voice from absolute energy and ZCR, that uses 12 difference Cepstrum from LPC, that uses the method to compensate the process of pattern separating and pre-calculated standard pattern limitation.

  • PDF

전부 주조관 제작을 위한 내화모형재 분리에 관한 연구 (A Study about the Separation of the materials Used in Refractory Cast Dies For Making All Ceramic Crowns)

  • 신무학;김연수;최운재
    • 대한치과기공학회지
    • /
    • 제21권1호
    • /
    • pp.123-130
    • /
    • 1999
  • I attempted to suggest a better method to separate a refractory cast in order to solve the problems caused by bonding between refractory casts and ceramics in the firing-processing of all ceramic crowns as a part of dental prosthodontics. I emphasize the advantages and effectiveness of easy separation after firing by using the separating materials about the refractory cast dies. 1. We must not usse HF(55%) that is used as the chemical separating methods. 2. We decrease such methods as grinding, blasting, bur, and point 3. We can save time, costs and manual labors by using this methods. 4. This method regulates the expansion and constriction of heat because of the chemical reaction of the separating materials. 5. This method contribute to the breaking down without modification by minimizing the chemical and mechanical damages of the marginal and interior parts.

  • PDF

실시간 쿼드로터 자율주행과 원격제어 기법 (A Real Time Quadrotor Autonomous Navigation and Remote Control Method)

  • 손병락;강석민;이현;이동하
    • 대한임베디드공학회논문지
    • /
    • 제8권4호
    • /
    • pp.205-212
    • /
    • 2013
  • In recent, the demand of Unmanned Aerial Vehicles (UAVs) that can autonomous navigation and remote control has been increased in military, civil and commercial field. Particularly, existing researches focused on autonomous navigation method based on vanish point and remote control method based on event processing in indoor environments. However, the existing methods have some problems. For instance, a detected vanish point in intersection point has too much detection errors. In addition, the delay is increased in existing remote control system for processing images in real time. Thus, we propose improved vanish point algorithm by removing detection errors in intersection point. We also develop a remote control system with android platform by separating flying control and image process. Finally, we compare the proposed methods with existing methods to show the improvement of our approaches.