• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.451-456
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• 2009

In this paper, a virtual force is generated and fed back to the operator to make the teleoperation more reliable, which reflects the relationship between a slave robot and an uncertain remote environment as a form of an impedance. In general, for the teleoperation, the teleoperated mobile robot takes pictures of the remote environment and sends the visual information back to the operator over the Internet. Because of the limitations of communication bandwidth and narrow view-angles of camera, it is not possible to watch certain regions, for examples, the shadow and curved areas. To overcome this problem, a virtual force is generated according to both the distance between the obstacle and the robot and the approaching velocity of the obstacle w.r.t the collision vector based on the ultrasonic sensor data. This virtual force is transferred back to the master (two degrees of freedom joystick) over the Internet to enable a human operator to estimate the position of obstacle at the remote site. By holding this master, in spite of limited visual information, the operator can feel the spatial sense against the remote environment. It is demonstrated by experiments that this collision vector based haptic reflection improves the performance of teleoperated mobile robot significantly.

• Journal of Korea Multimedia Society
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• v.12 no.11
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• pp.1652-1660
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• 2009

The main objective of this research is to build a behavior prediction model of gameplay for MMO (Massively Multiplayer Online) game using the GOMS analysis method. GOMS analysis is an observational approach to HCI(Human Computer Interaction) to model and predict behaviors of a human operator in a highly interactive task. In this research, a pilot experiment was previously conducted with three skilled gamers. The gamers were provided with the goals and operators through the user's guide book, and they found methods and selection rules while being observed. Based on the results obtained from the pilot study, this research was expanded and the model was further tested with 30 subjects (game experts). The new outcomes revealed that the relevance of GOMS analysis for predicting selection rules is 96.25% according to the degree of abstraction and 77.35% based on the degree of complexity. This research will provide game designers with a new testing mechanism in the early development stages, in order to improve the quality of the game product.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.2
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• pp.87-96
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• 2012

With a view to determine a safe speed the limit of a manipulator arm, several experiments was performed with a multi-jointed manipulator in maintenance and decommissioning tasks of nuclear facilities. Under the simulated emergency conditions, which were generated with random combinations of manipulator arm speed, failure probability and failure type, response characteristics of human operators to various malfunctions of a manipulator arm were measured in terms of reaction time, number of false alarm, and number of misses. This paper demonstrated that failure type, manipulator axes and manipulator arm speed has significant effects on human reaction time. As a whole the reaction time was slightly increased with manipulator arm speed, which is showed somewhat different pattern due to failure type. The reaction time to an axis acting on a workpiece directly, which could flex and extend, was fastest and much more its standard deviation was small. Various factors which may affect safe speed were also described.

• Journal of the Korean Society of Systems Engineering
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• v.12 no.2
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• pp.81-90
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• 2016

The system performance of Engineered Safety Features is of utmost importance in a nuclear power plant. The human performance is identified as most critical to assurance of the optimal operability of safety systems during an emergency. The aim of this study is to determine how the performance of safety system could be evaluated using Augmented Reality technology. The paper presents a description of how a systems engineered approach could be used to develop the necessary operating conditions needed to conduct this measurement. Augmented Virtual Reality (AVR) interface technology is achieving ease of availability and widespread use in many applications today as illustrated by the launch of several AR and VR devices aimed at media consumption. As such, environments that incorporate such AVR hardware have become invaluable tools in designing human interface systems because of the high fidelity and intuitive response to natural human interaction that can be achieved [2]. The outcome of the measurement undertaken is to determine whether 1.) Operator(s) performance can be enhanced by introducing an improved cognitive method of monitoring plant information during an Emergency Operating Procedures (EOP) and 2.) In correlation, inform the performance of the diverse safety systems on the basis of human factors.

• Journal of the Ergonomics Society of Korea
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• v.17 no.1
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• pp.47-54
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• 1998

Product design and development is very important process in enterprise activities. Reducing development time and reflecting consumer's needs is required to product design and development for increasing benefit and decreasing cost. Human sensibility ergonomics is one of the important technology of R&D in product development. However, the subjective method of human sensibility ergonomics has several problems to analyze and to Quantify experimental data and objective method of human sensibility ergonomics is still in process on study. In this research, new analyzing method is proposed for the subjective human sensibility ergonomics applied with fuzzy set theory. What is the useful theory for controlling uncertain type of information like human mind? This approach is more effective method for analyzing consumer's needs for product design and development process. At collecting needs, certainty scale is added for adapting hedge of fuzzy function. Using a kind of union operator, synthesize each item to analyze identification of each item with fuzzy hamming distance. Identification of analysis is classified with the relational weight using Relationship Chart Method, and is drawn the relationship diagram for clustering each item. A case study with sample test is conducted and demonstrated with this suggested method for more effective way.

• Journal of the Ergonomics Society of Korea
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• v.7 no.2
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• pp.31-44
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• 1988

If an error occurs in the automatic mode when the advanced teleoperator system performs a task in hostile environment then the automatic mode changes into the manual mode. The operation by the control program and the operation by a human recover the error in the manual mode. The system resumes the automatic mode and continues the given task. It is necessary to improve the manual mode in order to make the best use of a man-robot system, as a part of the human interface technique. Therefore, the error recovery task is performed by combining the operation by the control program representing autonomy of a robot and the operation by a human representing versatility of a human operator effectively in the view point of human factors engineering. The geometric inverse kinematics is used for the calculation of the robot joint values in the operation by the control program. The singularity operation error and the parameter operation error often occur in this procedure. These two operation errors increase the movement time of the robot and the coordinate reading time, during the error recovery task. A singularity algorithm, parameter algorithm and fuzzy control are studied so as to remove the disadvantages of geometric inverse kinematics. And the geometric straight line motion is studied so as to improve the disadvantages of the operation by a human.

• Journal of the Ergonomics Society of Korea
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• v.19 no.1
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• pp.1-9
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• 2000

This study was performed to investigate some characteristics on human error proneness in the computerized work environment. Our concerning theme was on human error likelihood according to personal temperament. Two experiments were performed. The first experiment was to study the effect of field- independence/dependence on error likelihood. The second experiment was on error proneness. These experiments were performed in information search task. which was most frequent task in computerized work environment such as the control room of nuclear power plant. Ten subjects were participated in this study. Analyzed results are as follows. Field-independence/dependence had a significant effect in both information search time and error frequency. Error proneness had a significant effect in both factors, too. And, a positive correlation was found between error frequency and information search time. These results will be utilized as a basis to study operator's error proneness in the computerized control room of nuclear power plant. later on.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.12
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• pp.977-983
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• 2005

In this paper, novel ubiquitous concept of real reality robot game controlled by a mobile server robot is proposed. Real reality robot game means that two real robots controlled by humans/computers through the internet are playing a boxing game. The mobile server robot captures playing images of the boxing game and sends them to GUI on the screen of human operators' PC. The human operator can login to the boxing game from any computer in any place if he/she is permitted. Remote control of a boxing robot by a motion capture system through network is implemented. Successful motion control of a boxing robot remotely controlled by a motion capture system through network can be achieved. In addition, real boxing games between a human and a computer are demonstrated.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.403-406
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• 1996

Since most human activities in a nuclear power plant are perfirmed in the main control room (MCR), it is important to have its design well human-engineered, both physically and cognitively. Much research efforts have been given for better, operator-centered designs of human-machine interface in MCR capitalizing today's advanced information technology. Korea is among those who are actively expending such research for the next-generation nuclear plants. This paper analyzes two forerunners among the emerging MCR designs, namely Nuplex 80+ and N4, from the perspective of cognitive systems engineering. Since the two show some fundamental differences in their design concepts, the principles with their pros and cons must be enumerated to benefit our own design of new control rooms. This paper also lists many other decision-making points that emerged due to the new availability of cognitively based on cognitive engineering principles. The future scope and directions of related research are suggested.

• Journal of the Ergonomics Society of Korea
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• v.18 no.3
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• pp.1-12
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• 1999

This study investigated human operator's perceptual and psychophysical responses to vibrotactile stimulation on various parts of the hand. Using a small vibrotactile display, the effects of three mechanical parameters consisting vibrotactile stimulations, i.e., vibration frequency, pulse-width modulation duty cycle, and number of contactors, on differential thresholds were examined at five different loci of the hand. It was observed that differential threshold varies with vibration frequency and number of active contactors. Differential sensitivity was the greatest at the vibration frequency of 120 Hz. The differential sensitivity was not found to be affected by loci on the hand. The area of stimulation on the hand was also found to be significant in that the sensitivity increased with the number of active contactors. It should be noted that the conclusions from this study generally correspond to those from the previous study on the absolute sensitivity. which means that tactile sensitivity to vibrotactile stimulations can be controlled with a systematic and consistent passion for emulating normal everyday contact on human hands in teleoperation and virtual reality applications.