• The Transactions of the Korean Institute of Electrical Engineers
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• v.35 no.5
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• pp.177-184
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• 1986

An effective cartesian coordinate model is presented to control a robot motion along a prescribed timebased hand trajectory in cartesian coordinates and to provide an adaptive feedback design approach utilizing self-tuning control methods without requiring a detailed mathematical description of the system dynamics. Assuming that each of the hybrid variable set of velocities and forces at the cartesian coordinate level is mutually independent, the dynamic model for the cartesian coordinate control is reduced to first-order SISO models for each degree of freedom of robot hand, including a term to represent all unmodeled effects, by which the number of parameters to be identified is minimized. The self-tuners are designde to minimize a chosen performance criterion, and the computed control forces are resolved into applied joint torques by the Jacobian matrix. The robustness of the model and controller is demonstrated by comparing with the other catesian coordinate controllers.

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.73-79
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• 1997

Governments and industry have a growing interest in the harmonization of environmental test methods and risk assessment procedures. OECD are currently producing a set of harmonised test guidelines for studying the environmental fate and ecological effects of pesticides. FAO has published an environmental risk assessment procedure. This procedure, which is similar to those used in US and Europe, is based on calculating the ratio of the toxicity of a pesticide to indicator organisms to their level of exposure to the pesticide. The exposure depends on both the concentration of the pesticide and its bioavailability. Ratios which indicate a pesticide will not produce a harmful effect have been established using ecological field studies. Examples are presented for assessing the risk to aquatic ecosystems, earthworms and honeybees. Long-term field studies(up to 20 years) have also shown that pesticides can be used indefinitely without harming soil fertility. Herbicides can be used to avoid the ecologically damaging effects of using soil cultivations excessively for weed control.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.6
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• pp.601-607
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• 2010

For commercial success of emerging service robots, the fault tolerant technology for system reliability and human safety is crucial. Traditionally fault tolerance methods have been implemented in application level. However, from our studies on the common design patterns in fault tolerance, we argue that a framework-based approach provides many benefits in providing reliability for system development. To demonstrate the benefits, we build a framework-based fault tolerant engine for OPRoS (Open Platform for Robotic Services) standards. The fault manager in framework provides a set of fault tolerant measures of detection, isolation, and recovery. The system integrators choose the appropriate fault handling tools by declaring XML configuration descriptors, considering the constraints of components and operating environment. By building a fault tolerant navigation application from the non-faulttolerant components, we demonstrate the usability and benefits of the proposed framework-based approach.

• Journal of Mechanical Science and Technology
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• v.17 no.12
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• pp.1986-1993
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• 2003

The spatially resolved spray volume fractions from both line-of-sight data of direct measuring cells and a laser diffraction particle analyzer (LDPA) are tomographically reconstructed by the Convolution Fourier transformation, respectively. Asymmetric sprays generated from a twin-hole injector are tested with 12 equiangular projections of measurements. For each projection angle, a line-of-sight integrated injection rate was measured using a direct sampling method and also a liquid volume fraction from a set of line-of-sight Fraunhofer diffraction measurements was measured using a light extinction method. Interpolated data between the projection angles effectively increase the number of projections, significantly enhancing the signal-to-noise level in the reconstructed data. The reconstructed volume fractions from the direct sampling cells were used as reference data for evaluating the accuracy of the volume fractions from the LDPA.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.387-392
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• 1992

This paper presents a local trajectory generation method which is based on a sequence of reference posture-velocities and the efficient low level control algorithm which constructs the complete smooth curve from the trajectory specification. The reference trajectory generator(RTG) which is in between the local path planner(LPP) and the robot motion controller(RMC) generates a sequence of set-points for each path segments from the LPP and pass it to the RMC. The RMC controls the motions of vehicle which should follow the sequence. In the feedback controller of VMC, the method which compensates robot posture-velocity error correctly is used. These methods are implemented on indoor autonomous vehicle, 'ALIVE' mobile robot. The ALIVE mobile robot system is implemented on the 32bit VME bus system: the two VME CPU's are used for RTG and RMC, while the 80C196KC-based VME board is used for motor controller.

• Nuclear Engineering and Technology
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• v.44 no.8
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• pp.847-854
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• 2012

Despite extensive research efforts, the mechanism of the nucleate boiling phenomena is still not clear. A direct numerical simulation of the boiling phenomena is one of the promising approaches in order to clarify its heat transfer characteristics and discuss their mechanism. Therefore, many DNS procedures have been developed based on recent highly advancing computer technologies. This brief review focuses on the state of the art in direct numerical simulation of the pool boiling phenomena over the past two decades. In this review, the fundamentals of the boiling phenomena and the bubble departure and micro-layer models are briefly introduced, and then the numerical procedures for tracking or capturing interface/surface shape such as the front tracking method, level set method, volume of fluid treatments, and other methods (Lattice Boltzmann method, phase-field method and so on) are briefly reviewed.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.191-196
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• 2001

The conventional methods for noise control attempts to simply reduce the level of product noise. This has been common practice in noise control industry. However, it is very straightforward common sense that we have consider human perception on noise. In this paper, we propose a noise control strategy which takes into account the subjective perception of product noise. We especially has concentrated on a refrigerator noise. The proposed method is composed of 3 steps. Firstly, the actual refrigerator noise signal is measured. Then, to make the sample noise set for subjective assessment the noise signal is edited in 1／3 octave bands. Finally, we establish a strategy of refrigerator noise control by using the results from subjective assessment of these noise signals

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.388-388
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• 2000

The complexity of nonlinear systems makes it difficult to ascertain their behavior using classical methods of analysis. Many efforts have been focused on the advanced algorithms and techniques that hold the promise of improving real-time optimal control while at the same time providing higher accuracy. In this paper, a fuzzy cell mapping method of real-time optimal control far nonlinear dynamical systems is proposed. This approach combines fuzzy logic with cell mapping techniques in order to find the optimal input level and optimal time interval in the finite set which change the state of a system to achieve a desired obiective. In order to illustrate this method, we analyze the behavior of an inverted pendulum using fuzzy cell mapping.

• International Journal of Contents
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• v.15 no.4
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• pp.50-58
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• 2019

Baotu Spring Park, a must-visit place in Jinan, China, has been rated as the country's highest-level scenic spot by the Chinese government. However, social media that highly reflects public opinions tends to express a lower evaluation of Baotu Spring Park. Thus, this paper employs service design thinking methods to identify the problems of Baotu Spring Park and provide solutions from the perspective of visitors. Based on desk research, tourist behavior tracking, contextual interviews, and a customer journey map, it was found that the service gap of Baotu Spring Park lacks a unified and effective instruction system. Also, the activities, parking, and high-quality tourist souvenirs are deficient, and there is no online information delivery platform. Finally, five suggestions are made,-respectively:,- redesign the sign system, enhance the participation of tourists, redesign the tourist souvenirs and display space, offer parking areas and shuttle buses, as well as set up a dedicated application.

• Journal of Korean Physical Therapy Science
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• v.19 no.4
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• pp.41-46
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• 2012

Background : The purpose of this study was to investigate the electromyographic(EMG) amplitude of the gluteus medius muscle bilaterally at various hip angles and motions(flexion, extension and abduction). Methods : Thirty young with a mean(SD) age of 21.03(1.69) years performed hip motions(flexion, extension and abduction) while the surface EMG activity of the gluteus medius muscles was recorded bilaterally. Subjects were instructed to use the right lower limb during moving 3 different direction. Differences in EMG amplitudes in according with movement direction and angle were assessed by use of paired t-test analyses of variance for the right and left lower extremities. The alpha level was set at .05. Results : Gluteus medius muscle EMG activities in the both side were significantly greater for abduction at angles of 30 degrees than those for other motions at other angles. Conclusion : Hip abduction at angles of 30 degrees on the standing position may be effective in activating the gluteus medius muscle.