• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국제학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.234-239
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• 1993

Most of the control problem is for the redundant manipulators use the pseudo-inverse control, thit is, the redundancy is resolved by the pseudo-inverse of the Jacobian matrix and then the controller is designed based on this resolution. However, this pseudo-inverse control has some problems when the redundant robot repeats the cyclic tasks. This is because the pseudo-inverse resolution is a local solution that generates the different configurations of the robot arm for the same hand position. Therefore it is necessary to find the global solution that maintains the optimal configuration of the robot for the repetitive tasks. In this paper, we want to propose a redundancy resolution method by the optimal theory that uses the calculus of variation. The problem formulations are : first to convert the optimal resolution problem to an optimal control problem and then to resolve the redundancy using the necessary conditions of optimal control.

• Geomechanics and Engineering
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• 제35권5호
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• pp.555-570
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• 2023

In the current study, a series of experimental and analytical evaluations were performed to introduce the horizontal pseudo static coefficient (kh) as a function of the wall configuration and the reinforcement type for analyzing reinforced soil walls. For this purpose, eight shaking table tests were performed on reduced-scale models of integrated and two-tiered walls reinforced by metal strip and geogrid to determine the distribution of dynamic lateral pressure in the walls. Then, the physical models were analyzed using Mononobe-Okabe method to estimate the value of kh required to establish the dynamic lateral pressures similar to those observed in shaking table tests. Based on the results, the horizontal pseudo static coefficient and the position of resultant lateral force (R) were introduced as a function of the horizontal peak ground acceleration (HPGA), the wall configuration, the reinforcement type as well as maximum wall displacement.

• 제어로봇시스템학회논문지
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• 제13권9호
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• pp.896-902
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• 2007

This paper proposes a vision-based kinematic control method for mobile robots with camera-on-board. In the previous literature on the control of mobile robots using camera vision information, the forward velocity is set to be a constant, and only the rotational velocity of the robot is controlled. More efficient motion, however, is needed by controlling the forward velocity, depending on the position in the corridor. Thus, both forward and rotational velocities are controlled in the proposed method such that the mobile robots can move faster when the comer of the corridor is far away, and it slows down as it approaches the dead end of the corridor. In this way, the smooth turning motion along the corridor is possible. To this end, visual information using the camera is used to obtain the perspective lines and the distance from the current robot position to the dead end. Then, the vanishing point and the pseudo desired position are obtained, and the forward and rotational velocities are controlled by the LOS(Line Of Sight) guidance law. Both numerical and experimental results are included to demonstrate the validity of the proposed method.

• 생명과학회지
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• 제14권1호
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• pp.32-37
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• 2004

ITS2 부위를 시퀀싱하여 Pseudo-nitzschia delcatissima, P. multiseries, P. pungens, P. subfraudulenta 상호간의 유전자 다양도를 조사함과 아울러 RAPD-PCR pattern을 이용하여 유사도를 구하였다. 유전자 거리를 근거로 했을 때 P. delicatissima 종은 P. multiseries와 P. pungens와는 유전적 거리가 상당히 요원하였고, 심지어 P. subfraudenlta와도 거리를 보였다. 유사도의 경 P. multiseries와 P. pungens는 0.31로 보인 반면에, P delicatissima는 다른 세종과 0.81를 나타내었다. 따라서 P. delicatissima 종은 P. multiseries, P. pungens, P. subfraudulenta와는 유전적으로 밀접하지 않는 관계로 보였다. ITS2부위는 Pseudo-nitzschia 동정에 사용될 수 있는 유용한 도구로 보이며 형태적으로 구분할 수 없는 P. multiseries와 P. pungens을 구분할 수 있다. 또한 RAPD-PCR 방법도 단시간에 Pseudo-nitzchia을 분리시키는데 사용될 것으로 보인다.

• 한국공작기계학회논문집
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• 제10권3호
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• pp.83-89
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• 2001

In this paper, we discuss the vibration suppression control of spatial redundant flexible manipulators through pseudo-inversed of Jacobian. In order to verify our method, the experiments are performed for PTP(Point To Point) motion of spa-tial flexible manipulators(1) with no redundancy(2) with one redundant DOF(degree of freedom). Finally, a comparison between these results is presented to show the performance of out approach.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1622-1624
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• 1987

In general, pseudo noise generator(PNG) used for PLR System consists of linear feedback shift register. Based on a W.F. representation of shift registers, a method for analyzing operational characters & sequence of PNG are studied. PNG is characterized by the time-recursive equation & PNG sequence is analyzed by the output state variable equation. Methods studied in this paper are illustrated by appropriate example.

• Imaging Science in Dentistry
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• 제54권1호
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• pp.57-62
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• 2024

Purpose: This report presents a unique case featuring real, ghost, and pseudo-ghost images on the panoramic radiograph of a patient wearing earrings. It also explains the formation of these images in an easy-to-understand manner. Materials and Methods: One real image and two ghost images appeared on each side of a panoramic radiograph of a patient wearing earrings on both sides. Of the two ghost images on each side, one was considered a typical ghost image and the other was considered a ghost-like real image (pseudo-ghost image). The formation zones of the real, double, and ghost images were examined based on the path and angles of the X-ray beam from the Planmeca ProMax. To simulate the pseudo-ghost and typical ghost images on panoramic radiography, a radiopaque marker was affixed to the right mandibular condyle of a dry mandible, and the position of the mandible was adjusted accordingly. Results: The center of rotation of the Planmeca ProMax extended beyond the jaw area, and the area of double image formation also reached beyond the jaw. The radiopaque-marked mandibular condyle, situated in the outwardly extending area of double image formation, exhibited triple images consisting of real, double (pseudo-ghost), and ghost images. These findings helped to explain the image formation associated with the patient's earrings observed in the panoramic radiograph. Conclusion: Dentists must understand the characteristics and principles of the panoramic equipment they use and apply this understanding to taking and interpreting panoramic radiographs.

• Journal of Electrical Engineering and Technology
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• 제9권4호
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• pp.1437-1445
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• 2014

In this paper a novel method for angular position determination using sensors with sin/cos output and without an excitation signal, is presented. The linearization of the sensor transfer characteristic and digitalization of the measurement results are performed simultaneously with a goal to increase the measurement resolution. This improvement is particularly important for low angular velocities, and can be used to increase the resolution of incremental Hall, magnetic and optical sensors. This method includes two phases of sin/cos signal linearization. In the first linearization phase the pseudo-linear signal is generated. The second linearization phase, executed by the two-stage piecewise linear ADC, is an additional linearization of the pseudo-linear signal. Based on the LabVIEW software simulations of the proposed method, the contribution of each processing phase to a final measurement error is examined. After the proposed method is applied within $2{\pi}$ [rad] range, the maximal nonlinearity is reduced from 0.3307 [rad] ($18.9447^{\circ}$) to $3{\cdot}10^{-4}$ [rad] ($0.0172^{\circ}$).

• 한국항공우주학회지
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• 제45권9호
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• pp.757-765
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• 2017

위성항법시스템 (GNSS: Global Navigation Satellite System)으로 계산되는 위치 정확도는 위성 의사거리 (Pseudo-Range) 측정값 정확도와 DOP (Dilution of Precision) 으로 표현되는 위성의 배치관계를 통해 결정된다. 위성의 의사거리 측정값은 위성 시계, 궤도, 전리층, 대류층, 다중경로 등 여러 요인에 의해 오차가 발생하게 되며, 사용자 의사거리정확도를 향상을 위해서는 정확한 의사거리 측정값이 필요하다. 반면, 위성의 배치의 경우, 사용자의 수신환경에 따라 위치 정확도가 달라진다. 예를 들어, 고층 빌딩이 많은 도심의 경우에는 위성전파 차단의 위험이 많아 가시위성의 수가 감소하고 개활지에 비해 상대적으로 양호한 DOP을 가지기 어렵다. 본 논문은 가상위성 (Virtual Satellite)을 통해 DOP 성능 개선과 의미있는 가상거리측정값 (VRM: Virtual Range Measurement) 정확도를 확보하여, 위치 정확도 향상 시키는 방법에 대해 연구하였다. 그 결과 적절한 가상위성배치와 정확한 가상 거리측정값을 이용하면 수직위치 정확도의 개선 효과를 얻을 수 있었다.

• 한국통신학회논문지
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• 제41권12호
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• pp.1756-1758
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• 2016

의사거리는 GPS 수신기의 위치를 결정하기 위한 오차를 포함해 측정된 GPS 위성과 수신기 사이의 거리이다. 재방송 재밍기는 GPS 수신기에 가까이 있을 때 효과적으로 동작한다. 본 논문에서는 재방송 재밍의 원리를 효과적으로 이해하기 위해 근접한 GPS 수신기의 의사거리 차를 분석한다.