• 제목/요약/키워드: Loop method

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비균일 단일루프에서의 효율적인 루프 분할 방법 (An Efficient Loop Splitting Method on Single Loop with Non-uniform Dependences)

  • 정삼진
    • 한국콘텐츠학회논문지
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    • 제5권4호
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    • pp.204-211
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    • 2005
  • 본 논문은 비균일 단일루프의 병렬성을 향상시키기 위해서 지금까지 개발된 최소 종속 거리 분할 방법, Polychronopoulous 분할 방법, 그리고 최초 종속 분할 방법과 같은 세 가지 루프 분할 방법을 소개하며, 기존의 분할 방법의 문제점들을 제시한다. 그리고, 기존의 세 가지 루프 분할 방법 중에서 가장 효과적인 최초 종속 분할 방법을 확장하여 병렬성을 향상시킨 보다 강력한 루프 분할 방법을 제안한다 제안된 알고리즘은 역 종속성일 경우와 gcd(최대공약수)값이 1보다 클 경우와 같이 최초 종속 분할 방법에서 해결하지 못한 문제점들을 해결하였다.

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A Loop Transformation for Parallelism from Single Loops

  • Jeong, Sam-Jin
    • International Journal of Contents
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    • 제2권4호
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    • pp.8-11
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    • 2006
  • This paper describes several loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops into parallel loops.

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Loop-loop EM inversion and its applicability to subsurface exploration

  • Sasaki, Yutaka
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2006년도 공동학술대회 논문집
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    • pp.3-6
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    • 2006
  • There are three types of frequency-domain loop-loop EM induction method, depending on the loop separation and their location relative to the ground surface: horizontal-loop EM (HLEM), fixed small-loop EM, and helicopter-borne EM (HEM) methods. Multidimensional inversion provides tomographic images of the subsurface resistivity structure and thus enhances the interpretational accuracy of loop-loop EM data. HLEM method is shown to be effective for exploring groundwater resources in weathered and fractured crystalline basement terrains in semi-arid regions. Also, HEM method is useful for locating weak zones in landslide areas. The applicability of inversion to small-loop EM data depends solely on the S/N ratio. The quadrature response of small-loop EM data can only give the equivalent conductivity of a homogenous half-space model, and thus the in-phase component is essential in inverting EM data. However, the in-phase response is much lower and decreases more rapidly with decreasing frequency than the quadrature response. Further work is needed to obtain conductivity-depth images from small-loop EM data.

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Parallelism for Single Loops with Multiple Dependences

  • Jeong, Sam-Jin
    • International Journal of Contents
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    • 제3권3호
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    • pp.15-19
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    • 2007
  • We review some loop partitioning techniques such as loop splitting method by thresholds and Polychronopoulos' loop splitting method for exploiting parallelism from single loop which already developed. We propose improved loop splitting method for maximizing parallelism of single loops with non-constant dependence distances. By using the iteration and distance for the source of the first dependence, and by our defined theorems, we present generalized and optimal algorithms for single loops with non-uniform dependences. The algorithms generalize how to transform general single loops with one dependence as well as with multiple dependences into parallel loops.

확장 T-method에 의한 환상식 덕트시스템 해석 (Analysis of loop duct system by extended T-method)

  • 이승철;문종선;이재헌
    • 설비공학논문집
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    • 제10권4호
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    • pp.389-397
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    • 1998
  • A loop duct system is often found in a VAV-HVAC(variable air volume heating, ventilating and air conditioning) design. It is known that the simple T-method is not be applicable to the loop duct system and cannot be used to calculate the flow rate and the pressure drop at each duct section of the loop duct system. In this paper, the extended T-method has been developed and it is found to be applicable to the loop duct system to which the simple T-method cannot be applied. The validity of the extended T-method has been verified by using to solve for a simple, ideal loop duct system for which there exists analytical solution. In addition, the extended T-method is employed to compute the loop duct system of a real building with an area of 380$m^2$. The results show that the computed flow rate at the exit differs from the designed flow rate by a range of -13.6~43.5 %. Consequently, three design factors must be adjusted in order that the flow rate may be balanced. These include the duct sizes, in terms of their lengths and diameters, the sub-duct locations and the positioning of damper which is found upstream of the exit duct.

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궤환 제어를 이용한 시스템 규명 (System identification using the feedback loop)

  • 정훈상;박영진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2001년도 추계학술대회논문집 I
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    • pp.409-412
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    • 2001
  • Identification of systems operating in closed loop has long been of prime interest in industrial applications. The fundamental problem with closed-loop data is the correlation between the unmeasurable noise and the input. This is the reason why several methods that work in open loop fail when applied to closed-loop data. The prediction error based approaches to the closed-loop system are divided to direct method and indirect method. Both of direct and indirect methods are known to be applied to the closed-loop data without critical modification. But the direct method induces the bias error in the experimental frequency response function and this bias error may deteriorates the parameter estimation performance

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Space closing loop에 의해 야기되는 상악 절치부 이동양상에 관한 역학적 연구 (MECHANICAL ANALYSIS OF THE PATTERN OF MOVEMENT DURING RETRACT10N OF MAXILLARY INCISORS BY SPACE CLOSING LOOP)

  • 민상홍;윤영주;김광원
    • 대한치과교정학회지
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    • 제25권2호
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    • pp.143-152
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    • 1995
  • 이 연구는 다양한 형태의 closing loops의 activation에 따른 치주조직에서의 응력분포를 평가하고 상악 절치의 이동 양상을 예측하기 위하여 3차원 유한요소법에 의하여 시행되었다. 동시에 상악 절치의 견인시 사용되는 bull loop, key-hole loop, T-loop, combination loop 그리고 asymmetrical T-loop도 3차원 유한요소법에 의해 분석 되었다. 이 연구로부터 얻어진 결과는 다음과 같다. 1. 여러가지 형태의 공간폐쇄용 루프중 bull loop에서 가장 큰 수평력을 나타냈으며 , key-hole, combination loop, T-loop 순이었다. 이들 모두 치아이동의 양상은 uncontrolled tipping을 나타냈다. 2. Asymmetrical TMA T-loop에서는 수평력이 현저히 감소하였으며, 절치부위에 함입력이 나타났다. 3. 절치부에서 torque의 증가에 따라 모멘트가 증가하였고, 선형적인 증가를 보였다. 4. 모멘트의 증가에 따라 치아의 초기 이동양상은 uncontrolled tipping에서 치근이동 양상으로 변화되었다.

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Design of Multi-loop PID Controllers Based on the Generalized IMC-PID Method with Mp Criterion

  • Vu Truong Nguyen Luan;Lee Jie-Tae;Lee Moon-Yong
    • International Journal of Control, Automation, and Systems
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    • 제5권2호
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    • pp.212-217
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    • 2007
  • A new method of designing multi-loop PID controllers is presented in this paper. By using the generalized IMC-PID method for multi-loop systems, the optimization problem involved in finding the PID parameters is efficiently simplified to find the optimum closed-loop time constant in a reduced search space. A weighted sum Mp criterion is proposed as a performance cost function to cope with both the performance and robustness of a multi-loop control system. Several illustrative examples are included to demonstrate the improved performance of the multi-loop PID controllers obtained by the proposed design method.

다중수원을 활용한 멀티워터 루프시스템의 표준화방안 구축에 관한 연구 (A Study on Standardization Method Establishment of Multi Water-Loop System using Multi Water Resources)

  • 이현동;이준형;곽필재
    • 한국관개배수논문집
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    • 제21권1호
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    • pp.109-117
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    • 2014
  • Multi water-loop system is the efficient customer centered facilities of water supply by utilizing the multi water resources. Multi water-loop system is divided into various types. The system is classified potable and non-potable type. Mostly, the potable type utilizes surface water and ground water. However, the non-potable type utilize the multi water resources, such as rain water, sea water, reclaimed water, etc. Selective intake is possible when characteristics of region, physiographic condition and purpose of use are considered. For instance, downtown type, new-city type, agriculture type, island type are available. For development and application of these multi water-loop system, standardization is needed. For standardization, several methods are given; design principles, selection and composition method of multi water-loop system structure, BIM/GIS application method, safety inspection method. Consequently, a road map of design standardization method can be established. In this road map, there are three parts for the standardization of multi water-loop system. Three parts are the considerations, base material and ways of standardization. Design standardization become close when this road map followed by someone who plan the multi water-loop system. In this way, loop system's development is more efficient and economic. In hereafter research, each type's characteristic will be analysed and standardization methods can be established.

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궤환 모델 개선법을 위한 모드 분리 제어기 (Mode-decoupling controller for feedback model updating)

  • 정훈상;박영진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2004년도 춘계학술대회논문집
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    • pp.864-869
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    • 2004
  • A novel concept of feedback loop design for modal test and model updating is proposed. This method uses the closed -loop natural frequency information for parameter modification to overcome the problems associated with the conventional method employing the modal sensitivity matrix. To obtain new modal information from closed-loop system, controllers should be effective in changing modal data while guaranteeing the stability of closed-loop system. It is very hard to guarantee the stability of the closed-loop system with non-collocated sensor and actuator set. Ill this research, we proposed a controller called mode-decoupling controller that can change a target mode as much as the designer wants guaranteeing the stability of closed-loop system. This controller can be computed just using measured open-loop modeshape matrix. A simulation based on time domain input/output data is performed to check the feasibility of proposed control method.

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