• Proceedings of the ESK Conference
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• 1995.04a
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• pp.30-34
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• 1995

The operator's performance of nuclear power plants is affected by many performance shaping factors(PSF). The objective of this study is to find out the PSFs and their effect on the nuclear power plant operations. We extracted PSFs in five category, and identified the relationships between PSFs and performance using the four survey methods; literture survey, case study, video task analysis and questionnaire survey. Finally the knowledge on PSFs and their effect was represented as rule form for cognitive simulation.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.303-309
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• 1997

This study is carried out to investigate performance differences between two alarm presentation methods from the viewpoint of human factors and to provide items to be improved. One of the alarm display methods considered in this study displays alarm lists on VDT combined with hardwired alarm panels. The other method displays alarms on plant mimic diagrams of VDT. This alarm display method has other features for operator aid with which operator can get detailed information on the activated alarm in the mimic diagrams, and the capability for alarm processing such as alarm reduction and prioritization. To compare the twodisplay methods, a human factor experiment was performed with a plant simulator in the ITF(Integrated Test Fcility) that plant operators run for 4 event scenarios. During the experiment, physiological measurements, system and operator action log, and audio/video recordings were collected. Operators' subjective opinion was collected as well after the experiment. Time, error rate and situation awareness were major human factor criteria used for the comparison during the analysis stage of the experiment. No statistical significance was found in the results of our statistical comparison analysis. Several findings were identified, however, through the analysis of subjective opinions.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.6
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• pp.605-612
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• 2015

Three dimensional (3D) position determination and motion recognition using a 3D depth sensor camera are applied to a developed penguin-shaped robot, and its validity and closeness are investigated. The robot is equipped with an Asus Xtion Pro Live as a 3D depth camera, and a sound module. Using the skeleton information from the motion recognition data extracted from the camera, the robot is controlled so as to follow the typical three mode-reactions formed by the operator's gestures. In this study, the extraction of skeleton joint information using the 3D depth camera is introduced, and the tracking performance of the operator's motions is explained.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.5
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• pp.94-102
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• 2003

This paper presents active management of feeder automation systems using active database. DAS(Distribution Automation System) has been managed for feeder automation in passive manner. Therefore, feeder automation system has to be managed by operator when feeder overloadings is detected. It may be possible for propagating the feeder overloadings area by operator's mistake. To overcome this defect, the author proposed the feeder automation technique with active manner to obtain feasible feeder reconfiguration. Active database can manage feeder automation system by data driven monitoring of events and by corresponding actions without operator's intervening. To manage feeder automation system with active manner, production rule, active rule manager are designed. And active database system architecture for feeder automation system is proposed. Test results on the KEPCO's 108 bus distribution system show that the performance is efficient and robust.

• Journal of the Korean Mathematical Society
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• v.51 no.4
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• pp.679-702
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• 2014

Investigation of the numerical solution of singularly perturbed turning point problems dates back to late 1970s. However, due to the presence of layers, not many high order schemes could be developed to solve such problems. On the other hand, one could think of applying the convergence acceleration technique to improve the performance of existing numerical methods. However, that itself posed some challenges. To this end, we design and analyze a novel fitted operator finite difference method (FOFDM) to solve this type of problems. Then we develop a fitted mesh finite difference method (FMFDM). Our detailed convergence analysis shows that this FMFDM is robust with respect to the singular perturbation parameter. Then we investigate the effect of Richardson extrapolation on both of these methods. We observe that, the accuracy is improved in both cases whereas the rate of convergence depends on the particular scheme being used.

• Journal of Institute of Control, Robotics and Systems
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• v.16 no.10
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• pp.997-1005
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• 2010

Most motion control systems consist of a desired trajectory generator, a motion controller such as a conventional PID controller, and a plant to be controlled. The desired trajectory generator as well as the motion controller is very important to achieve a good tracking performance. Especially, if the desired trajectory is generated actively utilizing the maximum velocity, acceleration, jerk and snap as given system specifications, the tracking performance would be better. For this, we make use of the properties of convolution operator in order to generate a smooth (S-curve) trajectory satisfying the system specifications. Also, the proposed trajectory generation method is extended to more general cases with arbitrary initial and terminal conditions. In addition, the suggested trajectory generator can be easily realized for real-time implementation. Finally, the effectiveness of the suggested method is shown through numerical simulations.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.2
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• pp.80-85
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• 2016

This study suggests a process design using cognitive processes. Job characteristic model for job design and recent cognitive engineering studies for process design are reviewed briefly. By using these concepts, the lean production system is re-interpreted in terms of cognitive engineering and the latent dimensions of the lean production system are revealed as the application of cognitive engineering principles. An integrated process design framework for cognitive manufacturing system using job characteristic model is suggested for the effective design of manufacturing system. Propositions for empirical analysis of this model are also analyzed through a questionnaire survey. Propositions are (1) experiential cognition and motivation potential affect the ability, role perception, and need for achievement of the operator in the manufacturing system, (2) the ability, role perception, and need for achievement of the operator affect the job performance. Both propositions are supported by correlation analysis and path analysis.

• Journal of Navigation and Port Research
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• v.48 no.3
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• pp.214-220
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• 2024

Remote control is used for operating maritime autonomous surface ships. The operator controls the ship using control data generated by the remote control system. To ensure successful remote control, three principles must be followed: safety, reliability, and availability. To achieve this, the suitability of both the control data and operators for remote control must be established. Currently, there are no international regulations in place for evaluating remote control suitability through experiments on actual ships. Conducting such experiments is dangerous, costly, and time-consuming. The goal of this study is to develop a suitability evaluation method using the output values of control devices used in actual ship operation. The proposed method involves evaluating the suitability of data by analyzing the output values and evaluating the suitability of operators by examining their tracking of these output values. The experiment was conducted using a shore-based remote control system to operate the training ship 'Hannara' of Korea National Maritime and Ocean University. The experiment involved an iterative process of obtaining the operator's tracking value for the output value of the ship's control devices and transmitting and receiving tracking data between the ship and the shore. The evaluation results showed that the transmission and reception performance of control data was suitable for remote operation. However, the operator's tracking performance revealed a need for further education and training. Therefore, the proposed evaluation method can be applied to assess the suitability and analyze both the control data and the operator's compliance with the three principles of remote control.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.185-190
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• 1995

Conventional alarm system has many difficulties in the operator's identifying the plant status during special situations such as design basis accidents. To solve the shortcomings, an on-line alarm annunciator system, called dynamic alarm console (DAC), was developed. In the DAC, a signal is generated as alarm by the use of an adaptive setpoint check strategy based on operating mode, and time delay technique is used not to generate nuisance alarms. After alarm generation, if activated alarm is a level precursor alarm or a consequencial alarm, it would be suppressed, and the residual alarms go through dynamic prioritization which provide the alarms with pertinent priorities to the current operating mode. Dynamic prioritization is achieved by going through the system- and mode-oriented prioritization. The DAC has the alarm hierarchical structure based on the physical and functional importance of alarms. Therefore the operator can perceive alarm impacts on the safety or performance of the plant with the alarm propagation from equipment level to plant functional level. In order to provide the operator with the most possible cause of the event and quick cognition of the plant status even without recognizing the individual alarms, reactor trip status tree (RTST) was developed. The DAC and the RTST have been simulated with on-line data obtained from the full-scope simulator for several abnormal cases. The results indicated that the system can provide the operator with useful and compact information fur the earlier termination and mitigation of an abnormal state.

• Journal of the Korean Institute of Intelligent Systems
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• v.25 no.2
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• pp.97-104
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• 2015

A fuzzy controller and a 2-dimensional wire-driven heavy material lifting system helping human operator are proposed in this paper. The 2-dimensional wire-driven heavy material lifting system is a kind of human-assistive systems in which a human is involved in the control loop. Most of the existing human-assistive control systems cannot consider human operator's characteristic. To consider human operator's characteristic, human's operating motion and requirement of reducing operator's force to lift a heavy material are considered in the design process of the proposed fuzzy controller. The performance of the proposed system is verified by experiments.