• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.1
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• pp.85-94
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• 2014

Tolerance accumulation has serious effect on the performance of an assembled body. This paper proposes the method which analyzes tolerance accumulation using Monte Carlo Simulation. This method can predict tolerance distribution of fully assembled body using the dimensional tolerance distribution of each part to be assembled. In this analysis, it is assumed that the tolerance of each part has the nominal distribution or uniform distribution. This analysis method is applied to ECV(External Control Valve), and the accumulated tolerance of the fully assembled ECV is obtained from the analysis. The results show that initial tolerance given to each part do not meet the design requirement of ECV. Hence, the tolerances of each part are modified and the additional analysis with the modified tolerances yields the results which satisfy the design requirements of ECV.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.901-905
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• 1992

The manual procedure of drafting engineering design is fast becoming obsolete. One of the important areas in CAPP is to automate tolerance assignment which is encountered in mechanical part design. This paper presents an approach for automating tolerance assignment using CAD database and tolerancing database in CAD drawing. The system is consisted of four major functions feasture extraction, feaure inferencing, rule-based tolerance allocation, and automatic upating. Auto CAD R.II is employed as CAD system and a computer progran is developed by using Auto LISP on PC-386.

• The Korean Journal of Ecology
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• v.15 no.2
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• pp.173-180
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• 1992

Pb, Zn tolerance of phaseolus multiflorus was investigated, based on the elongation of root and stem, pollen Germination and progeny quality in various pb, zn concentrations. The result obtained by water culture showed that the growth of roots and steams of phaseolus multiflorus from pb-zn mine site is less inhivited than that of the control site. The flower of phaseolus multiflorus from which pollen was taken were grown without added pb, zn and percent germination of pollen observed in a range of pb, zn concentrations. The percent germination of pollen from pb-zn mine site was higher than the control site. phaseolus multiflorus collected at a pb-zn mine site and the control site was site were grown at different pb, zn concentrations, its progeny was retreated with same concentrations of pb-zn mine site was more vigorous than the control site. thus, pb-zn tolerance was able to expressed in both pollen and sporophytes.

• Journal of IKEEE
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• v.24 no.1
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• pp.170-177
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• 2020

This paper presents an open-fault tolerance control method for active neutral point clamped (ANPC) inverter with high frequency/low frequency (HF/LF) modulation. By applying the ANPC inverter with SiC MOSFETs and Si IGBTs, the system efficiency and performance can be improved compared to a Si-based inverter. HF/LF modulation is used for a megawatt-scale inverter to minimize the commutation loop. The open-switch failure in megawatt-scale inverter causes severe damage to load and huge expenses when the inverter has been shut-down. The proposed tolerance control of open-switch failure provides continuous operation and improved reliability to the ANPC inverter. The effectiveness of the proposed fault tolerance control is verified by simulation results.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.527-537
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• 2016

Recent automakers are trying to be more precise with the dimension check and moving parts to guarantee high quality and satisfy customer requirements. The aim of this paper is to investigate the design tolerance suitability of door operating mechanism linked arms, lever, and cam-shaft in a mobile air handling unit. These parts are complicated because doors, arms, lever and cam-shaft are connected nonlinearly in 3D. The current tolerance analysis method poses problems in design analysis because the moving doors are reasonably suitable for the AHU function. The 3-DCS analysis method provided useful results not only in establishing the inspection criteria for the quality control of products but also in enabling economical production. As a result, the vent door had $1.62^{\circ}{\sim}1.72^{\circ}$ and the defrost door had $0.84^{\circ}{\sim}0.9^{\circ}$ for the directly connected arms operating-type. For the lever connected arm operating-type, the foot door had $2.0^{\circ}{\sim}2.24^{\circ}$ tolerance, while the tolerance values satisfied the air flow volume distribution rate criteria in the AHU. Finally, the results have confirmed the design's tolerance suitability by using 3-DCS analysis at the early design stages. Reliability can be achieved by analyzing accumulated tolerance during the sub-parts assembly process and the moving mechanism linked especially by arms, lever, and cam-shaft.

• International Journal of Control, Automation, and Systems
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• v.6 no.3
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• pp.296-305
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• 2008

Whereas fault diagnosis has been the subject of intensive research since the 1970s, the design of fault tolerant systems is a recent research field which does not set its foundations in a unified framework and does not use a unified vocabulary. As a contribution to this special issue, this paper proposes an ontology for the problem of Fault Handling, that embeds the problem of Fault Tolerance.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.11
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• pp.943-951
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• 2003

A strategy for fault-tolerant gaits of autonomous legged robots is proposed. A legged robot is considered to be fault tolerant with respect to a given failure if it is guaranteed to be capable of walking maintaining its static stability after the occurrence of the failure. The failure concerned in this paper is a locked joint failure for which a joint in a leg cannot move and is locked in place. If a failed joint is locked, the workspace of the resulting leg is constrained, but legged robots have fault tolerance capability to continue static walking. An algorithm for generating fault-tolerant gaits is described and, especially, periodic gaits are presented for forward walking of a hexapod robot with a locked joint failure. The leg sequence and the formula of the stride length are analytically driven based on gait study and robot kinematics. The transition procedure from a normal gait to the proposed fault-tolerant gait is shown to demonstrate the applicability of the proposed scheme.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.874-877
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• 2004

This paper presents the bus controller analysis of a power control unit of GEO satellite with 3kW power output. The sensing error of bus voltage produce control signal of the shunt switch assembly and the battery power converter, and the tolerance of error signal generated decide the stability of proposed system. The worst case analysis considered for the initial tolerance, temperature effect, tolerance of end of life is peformed to verify a designed bus controller. And also, the stability of system proposed according to moving of zero and pole values by some component failures is analyzed.

• Journal of the Korea Safety Management & Science
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• v.2 no.1
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• pp.89-97
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• 2000

This paper shows the study for development inprocess measuring magnetic sensor for tolerance control, First, we fabricated and annealed sample amorphous ribbons which were made of ($CO_{0.94}$$Fe_{0.06}$)$_{79}$$Si_{2}$$b_{19}$ having near zero magnetostrictive. It had 12［$\mu\textrm{m}$］ of thickness, 10［mm］ of length, and 2.5［mm］ of width. Then, we measured the magnetic characteristics such as frequency dependency over impedance variation rate and position change over impedance variation. As the results of the evaluation, we found that the sample ribbons had excellent sensor characteristics. Then, we made sensors by using the sample ribbons, As the results of the measurements, it proved that the ribbon could be used as excellent magnetic sensor for which it was possible to control inprocess measurement within the tolerance range(~$\mu\textrm{m}$ ).

• Korean Journal of Environmental Agriculture
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• v.29 no.2
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• pp.159-164
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• 2010

Imidacloprid is a systemic insecticide which has been used widely in various crops to control insects. In the present study, we demonstrated that pre-treatment of imidacloprid significantly induced tolerance to drought in plant. Relative water content, chlorophyll levels, and recovery rate upon rehydration after drought stress in tobacco plants pre-treated with imidacloprid were higher levels than the control plants. Induced drought tolerance by imidacloprid treatments in red pepper was also demonstrated by measurement of recovery rate and fresh weight upon drought stress. Taken together, our results suggest that imidacloprid, in addition to exerting direct insecticidal activity, may also protect plants by induced tolerance to drought in plant.