• Title/Summary/Keyword: Range Constraint

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Perceiving the Orientation of Linear Edges from Kinetic Occlusion (운동 중첩에 의한 직선적 윤곽의 방위 지각)

  • Jung, Woo-Hyun;Chung, Chan-Sup
    • Korean Journal of Cognitive Science
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    • v.17 no.3
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    • pp.151-175
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    • 2006
  • A common constraint-range model was suggested to explain the extraction of edge orientation from kinetic occlusion and five experiments were performed to verify this model. Results of the experiments show that the subjects' ability to identify the orientation of the kinetic edge increases as the angle of common constraint-range decreases. If the common constraint-range was fixed, the number of occluded elements or the interval between them had no effect on the accuracy. These results indicate that in the edge extraction process from kinetic occlusion, the angle of common constraint-range plays more important role than the density of background texture, supporting the common constraint-range model.

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The Effects of Constraint-induced Movement Therapy on Affected Upper Limb Functions in Patients with Hemiplegia (뇌졸중 후 편마비 환자의 건측억제-환측유도 운동이 환측 상지기능에 미치는 효과)

  • Yoo, Gwang-Soo;Bae, Joung-Hee
    • Research in Community and Public Health Nursing
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    • v.17 no.4
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    • pp.482-491
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    • 2006
  • Purpose: Hemiplegia patients who were attacked by a stroke suffer from hemiplegic disabilities as well as motor disabilities. For them, rehabilitation cure is being carried out broadly. However, it is not enough for them to use the upper extremity than the lower extremity. For the use of the upper extremity, we examined the effect of constraint-induced movement therapy developed in this research on patients who experienced a stroke following hemiplegia. Method: For this study we selected 36 stroke patients who were registered at the community health center through accidental sampling, and assigned 21 of them to the experimental group, and 15 to the control group. The experimental group had constraint-induced movement therapy for 5 days and 7 hours a day from 9 to o'clock in the morning 9 to 4 o'clock in the afternoon 4 including warmup exercise and main exercise in the rehabilitation room, whereas the control group were restricted. Result: As a result of constraint-induced movement therapy, affected side elbow joint flexion range, side shoulder joint extension range and side shoulder joint of the flexion range of motions increased obviously in the experimental group compared to those in the control group. Conclusion: The result above clearly shows that constraint-induced movement therapy is an effective intervention for the rehabilitation of hemiplegia patients in increasing affected side elbow joint of the flexion range of motion, the shoulder joint extension, and the increase of flexion range of motion.

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A Timing Constraint Search Technique for a TMO based Real-time Process

  • Jeong, Yoon-Seok;Kim, Tae-Wan;Han, Sun-Young;Chang, Chun-Hyon
    • Journal of Information Processing Systems
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    • v.2 no.1
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    • pp.1-5
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    • 2006
  • Finding a valid timing constraint is one of the most important issues in the real-time monitoring area. To get the valid timing constraint, a developer executes a real-time process and changes the constraint on a regular basis. This is an exhaustive and time-consuming process. To improve this approach, we propose a timing constraint search technique. This technique uses two load models and one condition proposed in this paper to support the developer in determining the valid timing constraint range in an easy and systematic manner.

Study on the Observability of Calibration System with a Constraint Oprerator (구속연산자에 의한 보정 시스템의 관측성에 관한 연구)

  • Lee, Min-Ki;Kim, Tae-Sung;Park, Kun-Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.4
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    • pp.647-655
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    • 2003
  • This paper studies the observability of calibration system with a constraint movement by a constraint operator. The calibration system with the constraint movement need only simple sensing device to check whether the constraint movements are completed within an established range. However, it yields the concern about the poor parameter observability due to the constraint movements. This paper uses the QR-decomposition to find the optimal calibration configurations maximizing the linear independence of rows of a observation matrix. The number of identifiable parameters are examined by the rank of the observation matrix, which represents the parameter observability. The method is applied to a parallel typed machining center and the calibration results are presented. These results verify that the calibration system with low-cost indicators and simple planar table is accurate as well as reliable.

A Study on the LQG/LTR for Nonminimum phase plant : Optimal Approximation method (비 최소위상 시스팀에 대한 LQG/LTR 연구 - 최적 근사화 방법)

  • 서병설;강진식;이준영
    • 제어로봇시스템학회:학술대회논문집
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    • 1991.10a
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    • pp.191-196
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    • 1991
  • LQG/LTR method have a theoretical constraint that it cannot applied to nonminimum phase plant. In this paper, we suggest two methods of approximation of minimum phase plant for a given nonminimum phase plant to solve this constraint. Error is described by additive form which can reduce its magnitude in broad frequency range. A optimal approximation method was suggesetd by using Hankel operator theory and Nehari theory. It is showen by example that the methods suggested can resolve the frequency domain constraint arised in Stein and Athans approximation.

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A Study on the LQG/LTR for Nonminimum Phase Plant (I) : Optimal Approximation Method (비 최소위상 플랜트에 대한 LQG/LTR에 관한 연구(I) : 최적 근사 방법)

  • 강진식;서병설
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.10
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    • pp.972-980
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    • 1991
  • LQG/LTR method have a theoretical constraint that it cannot applied to nonminimum phase plant. In this paper we suggest two methods of approximation of minimum phase plant for a given nonminimum phase plant to solve this constraint. Error is described by additive form which can reduce its magnitude in broad frequency range. A optimal approximation method was suggested by using Hankel operator theory and Nehan theory it is shown by example that the methods suggested can resolve the frequency domain constraint arised in Stein and Athans approximation.

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Constraint-based fracture mechanics analysis of cylinders with internal circumferential cracks

  • Bach, Michael;Wang, Xin
    • Structural Engineering and Mechanics
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    • v.47 no.1
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    • pp.131-147
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    • 2013
  • In this paper, constraint-based fracture mechanics analyses of hollow cylinders with internal circumferential crack under tensile loading are conducted. Finite element analyses of the cracked cylinders are carried out to determine the fracture parameters including elastic T-stresses, and fully-plastic J-integrals. Linear elastic finite element analysis is conducted to obtain the T-stresses, and elastic-plastic analysis is conducted to obtain the fully plastic J-integrals. A wide range of cylinder geometries are studied, with cylinder radius ratios of $r_i/r_o$ = 0.2 to 0.8 and crack depth ratio a/t = 0.2 to 0.8. Fully plastic J-integrals are obtained for Ramberg-Osgood power law hardening material of n = 3, 5 and 10. These fracture parameters are then used to construct conventional and constraint-based failure assessment diagrams (FADs) to determine the maximum load carrying capacity of cracked cylinders. It is demonstrated that these tensile loaded cylinders with circumferential cracks are under low constraint conditions, and the load carrying capacity are higher when the low constraint effects are properly accounted for, using constraint-based FADs, comparing to the predictions from the conventional FADs.

Blocking-Artifact Reduction using Projection onto Adaptive Quantization Constraint Set (적응 양자화 제한 집합으로의 투영을 이용한 블록 현상 제거)

  • 정연식;김인겸
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.40 no.1
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    • pp.79-86
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    • 2003
  • A new quantization constraint set based on the theory of Projection onto Convex Set(POCS) is proposed to reduce blocking artifact appearing in block-coded images. POCS-based postprocessing for alleviating the blocking artifact consists of iterative projections onto smoothness constraint set and quantization constraint set, respectively. In general, the conventional quantization constraint set has the maximum size of range where original image data can be included, therefore over-blurring of restored image is unavoidable as iteration proceeds. The projection onto the proposed quantization constraint set can reduce blocking artifact as well as maintain the clearness of the decoded image, since it controls adaptively the size of quantization constraint set according to the DCT coefficients. Simulation results using the proposed quantization constraint set as a substitute for conventional quantization constraint set show that the blocking artifact of the decoded image can be reduced by the small number of iterations, and we know that the postprocessed image maintains the distinction of the decoded image.

Improvement of the Stratospheric Wind Analysis with the Climatological Constraint in the Global Three-Dimensional Variational Assimilation at Korea Meteorological Administration (3차원 변분법의 제한조건 적용을 통한 기상청 전지구 모델의 성층권 바람장 개선)

  • Joo, Sangwon;Lee, Woo-Jin
    • Atmosphere
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    • v.17 no.1
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    • pp.1-15
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    • 2007
  • A constraint based on climatology is introduced to the cost function of the three-dimensional variational assimilation (3dVar) to correct the error of the zonal mean wind structure in the global data assimilation system at Korea Meteorological Administration (KMA). The revised cost function compels the analysis fit to the chosen climatology while keeping the balance between the variables in the course of analysis. The constraint varies selectively with the vertical level and the horizontal scale of the motion. The zonally averaged wind field from European Centre for Medium-Range Weather Forecasts Re-Analysis 40 (ERA-40) is used as a climatology field in the constraint. The constraint controls only the zonally averaged stratospheric long waves with total wave number less than 20 to fix the error of the large scale wind field in the stratosphere. The constrained 3dVar successfully suppresses the erroneous westerly in the stratospheric analysis promptly, and has been applied on the operational global 3dVar system at KMA.

ENHANCEMENT THE SOUND TRANSMISSION LOSS OF POROELASTIC LININGS

  • Song, B.Heuk-Jin;Bolton, J.Stuart
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.606-611
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    • 2000
  • It has been noted that the low frequency absorption coefficient of a porous sample placed in a standing wave tube is affected by the nature of the sample's edge constraint. The edge constraint has the effect of stiffening the solid phase of the sample, which itself can be strongly coupled to the material's fluid phase, and hence the incident sound field, by viscous means at low frequencies. In recent work it has also been shown that such a circumferential constraint causes the low frequency transmission loss of a layer of fibrous material to approach a finite low frequency limit that is proportional to the flow resistance of the layer and which is substantially higher than that of an unconstrained sample of the same material. However, it was also found that the benefit of the circumferential edge constraint was reduced in a transitional frequency range by a shearing resonance of the sample. Here it will be shown that the effect of that resonance can be mitigated or eliminated by adding additional axial and radial constraints running through the sample. It will also be shown that the constraint effect can be modeled closely by using a finite element procedure based on the Biot poroelastic theory. Implications for low frequency barrier design are also discussed.

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