• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.245-248
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• 1997

The control modes used in teleoperation are position control mode, and rate control mode. This paper presents the problems of the conventional control modes, through simulation, proposes an intelligent mixed control mode that converts the operation mode between the position mode and the rate mode intelligently by judging the operator's intention using the real-time measurement data. The effectiveness of the proposed intelligent mixed control mode is demonstrated and compared to other typical control modes through simulation and actual experiment.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.3
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• pp.311-317
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• 1997

DTG(dynamically tuned gyroscope) is a sensor detecting disturbance in angle velocity control loop of EOTS(electro optical tracking system), which is used for the stabilization of gimbal. DTG is classified into rate mode or rate integrated mode according to operating mode. In this paper, basic principles and characteristics of DTG, depending on to operating mode, are compared and the model of rate integrated mode DTG is proposed. Also, the validity of the presented model is verified by computer simulations and experiments.

• Journal of Welding and Joining
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• v.15 no.2
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• pp.72-80
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• 1997

The spatter generation rate of GMA welding with $CO_2$ gas shielding was measured with the change of welding conditions such as wire feeding rate and welding voltage and then the results were analized with the accompanying changes in metal transfer mode and in bead geometry. The spatter generation rate (SGR) was relatively low not only wit the short circuit transfer but with the truely globular transfer mode. However, the SGR resulted with the mixed mode were consistantly high. The resultant wave pattern of mixed mode was due to the coexistance of short-circuit and globular transfer and characterized by the frequent appearance of instantaneous short circuit. Considering the result of SGR and that of bead geometry, it could be concluded that when the wire feeding rate (or welding current) was either low or high, the optimum bead shape could be obtained along with the low spatter generation. However, in the middle range of wire feeding rate, the optimum bead shape was only obtained in the mixed mode condition resulting in the high spatter generation.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.461-465
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• 1996

Position and rate control modes arc the two common modes for controlling remote manipulators with joysticks or hand controllers. Generally, position mode is easier for teleoperation than rate modes, when the manipulation work space is small or comparable to the human operator's control space. When the telemanipulator's work space is very large, human operator's control motion range must be large to allow telemanipulator's full range of motion resulting poor control resolution. One way to solve the poor resolution problem is to use indexing. However, rate mode can provide any higher degree of resolution without use of indexing. If two modes are mixed, master controller will be more convenient. The mixed mode algorithm, changes operating mode from position mode to rate mode or vise versa using fuzzy logic. The fuzzy logic algorithm, which has been designed to recognize the teleoperator's intended motion properly, provides an intelligence to a master controller.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.41 no.6
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• pp.165-173
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• 2004

H.264 is the newest international video coding standard that provides high coding efficiency. A macroblock in H.264 has 7 different motion-compensation block sizes in the Inter mode, and several different prediction directions in the Intra mode. In order to achieve as highest coding efficiency as possible, H.264 reference model employs complex mode decision technique based on rate-distortion (RD) optimization which requires high computational complexity. In this paper, we propose two techniques -'early SKIP mode decision' and 'selective intra mode decision' - which can further reduce the computational complexity. Simulation results show that without considerable performance degradation, the proposed methods reduce encoding time by 30% on average and save the number of computing rate-distortion cost by 72%.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.65-72
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• 2006

Experiments in methane-air low strain rate counterflow diffusion flames diluted with nitrogen have been conducted to study the behavior of flame extinction and edge flame oscillation in which flame length is less than the burner diameter and thus lateral conduction heat loss in addition to radiative heat loss could be remarkable at low global strain rates. Critical mole fraction at flame extinction is examined with velocity ratio and global strain rate. Onset conditions of edge flame oscillation and flame oscillation modes are also provided with global strain rate and added nitrogen mole fraction to fuel stream (fuel Lewis number). It is seen that flame length is closely relevant to lateral heat loss, and this affects flame extinction and edge flame oscillation considerably. Edge flame oscillations in low strain rate flames are experimentally described well and are categorized into three: a growing oscillation mode, a decaying oscillation mode, and a harmonic oscillation mode. The regime of flame oscillation is also provided at low strain rate flames. Important contribution of lateral heat loss even to edge flame oscillation is clarified.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.171-178
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• 1996

DCB(pure mode I) and CLS(mixed mode) tests were performed to investigate the effect of fracture mode on the interlaminar fracture of composite laminate. Mode I critical strain energy release rate was found to be $133J/m^2$ from the DCB test and total strain energy release rate decreased from $1, 270J/m^2$ as thickness ratio(tl/t) varied from 0.333 to 0.667 from the crease from the CLS test. Crack length had no effect on the total strain energy release rate and load was almost constant during the crack growth of the specimen which had the specific thickness ratio. Crack initiated when the stress of the strap ply reached constant stress $42kgf/mm^2$ which was found to be independent of the thickness ratio.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.6
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• pp.552-557
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• 2011

This paper presents experimental results on the energy-bounding approach to a rate-mode bilateral teleoperation control that can guarantee the robust system stability in variable time-delayed telecommunication environments. Previously, rate-mode energy bounding approach [15] was proposed and verified with experimental results using the simulated remote slave model. In this paper, a real experimental setup using an industrial robot (Denso) as a remote slave robot composed and conducted similar experiments with previous paper. In order to guarantee stability of the Denso when contacting with high impedance wall, velocity based impedance control modified by position based is used. Experimental results show that the rate-mode energy bounding approach can guarantee stable bilateral teleoperation system in the free and contact motion with variable time delay.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.1C
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• pp.34-44
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• 2008

In this paper, a new rate-distortion estimation method is proposed for fast rate-distortion optimized(RDO) mode decision in H.264 encoder. A bit-rate and distortion should be calculated by encoding and reconstruction of each macroblock mode in order to select the optimal RDO mode. To reduce the computations for getting them, a bit-rate and distortion is efficiently estimated in DCT domain. Simulation results show that the proposed method achieves computational saving about 81% of RDO mode decision and saves about 26% of total encoding time without noticeable degradation in coding performance.

• Tribology and Lubricants
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• v.36 no.3
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• pp.117-123
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• 2020

In this study, the effect of the pre-mild wear mode test condition on the subsequent severe wear behavior of carbon steel has been investigated when the wear mode is varied according to the sliding speed change during sliding contact. Two sliding speeds of 0.3 m/s and 3 m/s for the mild wear mode test have been chosen and a sliding speed of 1 m/s for the severe wear mode test. A mild wear mode test at two different sliding speeds has been carried out during the severe wear mode test and total sliding distance of the mild wear mode test has been changed at this time. As a result, it could be found that the wear rate of carbon steel under the severe wear mode test after performing a pre-mild wear mode test is significantly reduced, compared with that before performing. However, its wear rate was slightly higher than that under the mild wear mode test. Oxides produced during the pre-mild wear mode test have been found to play a significant role in reducing the wear rate under the subsequent severe wear mode test. In particular, it was found that the effect of a pre-mild wear mode test performed at the sliding speed of 3 m/s has more rapid and the reduction in the wear rate was greater than thst at the sliding speed of 0.3 m/s.