• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.17 no.32
• /
• pp.243-253
• /
• 1994

Work environments have been changed with the advent of new technologies, such as computer technology. The newer technologies, the more changes in our work conditions. However, human cognitive limits can't keep up with the change of work environments. Mental workload has been an important factors in designing modem work environments such as human-computer interaction. Designing man-machine systems requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under an urgent situation, human operator may suffer the work stress, work error, and resultant deleterious work performance. To describe the work performance in the urgent work situations, with time stress and dynamic event occurence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount system processing time, information density) were evaluated using such dependent variables as reaction time, number of error, and number of failure. The results of statistical anlysiss indicate that the amount of information effected on all of five dependent measure. Number of failure and number of secondary task score were effected by both amount of information and operational speed of system, but reaction time of secondary task were effected by both amount of information and information density.

• Journal of KIISE:Software and Applications
• /
• v.35 no.5
• /
• pp.297-305
• /
• 2008

We present a cleaning robot algorithm that can be implemented on low-cost robot architecture while the cleaning performance far exceeds the conventional random style cleaning through human-robot interaction. We clarify the advantages and disadvantages of the two notable cleaning robot styles: the random and the mapping styles, and show the possibility how we can achieve the performance of the complicated mapping style under the random style-like robot architecture using the idea of human-aided cleaning algorithm. Experimental results are presented to show the performance.

• Journal of Pharmaceutical Investigation
• /
• v.30 no.1
• /
• pp.51-54
• /
• 2000

A column-switching high performance liquid chromatographic method has been developed for the determination of a fluconazole in human plasma. Each plasma sample was centrifuged for 10 min at 5000 g. After an aliqout of the supernatant was taken to nylon microcentrifuge filter, these samples were centrifuged for 10 min at 5000 g. An aliqout of the supernatant was injected directly onto the HPLC column. Deionized water was run for 2 min at a flow rate of 1.0 ml/min to retain fluconazole in an extration column, while proteins and endogenous interferences were eluted to the waste. The analyte was then back-flushed onto an analytical column, $C_{18}$ reversed-phase column. The mobile phase for analytical column, 0.01 M sodium acetate (pH 5.0)-methanol (65:35, v/v), was run at a flow rate of 1.0 ml/min. The column effluent was monitored by ultraviolet detection at 261 nm. The retention time for fluconazole was 11.76 min in human plasma. The detection limit for fluconazole in human plasma was $0.2\;{\mu}g/ml$. No interference from endogenous substances was observed.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.21 no.47
• /
• pp.57-68
• /
• 1998

Work environments have been changed with the advent of new technologies, such as computer technology. However, human cognitive limits can't pace up with the change of work environment. Designing human-computer system requires knowledge and evaluation of the human cognitive processes which control information flow workload. Futhermore, under limited reaction time and/or urgent situation, human operator may the work stress, work error and resultant deleterious work environment. This paper evaluate the visual factors of major information processing factors(information density, amount of information, operational speed of speed)on operator performance of supervisory control under urgent(limited reaction time)environments which require deleterious work condition. To describe the work performance int the urgent work situations with time stress and dynamic event occurrence, a new concept of information density was introduced. For a series of experiments performed for this study, three independent variables(information amount, system proceeding speed, information density) were evaluated using five dependent variables. The result of statistical analyses indicate that the amount of information affected on all of five dependent measure. Number of failure and number of secondary task score were influenced by both amount of information and operational speed of system. However reaction time of secondary task were affected by both amount of information and information density. As a result, the deleterious factors for the performances seemed to be a scanning time to supervise each control panel. Consequently, a new display panel was suggest to reduce operator work load for scanning task showing better operator performance.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.25 no.6
• /
• pp.108-114
• /
• 2011

In order to mitigate the possible hazards from electric shock due to the touch and step voltages, the high resistivity material such as gravel is often spread on the earth's surface in substations. When the grounding electrode is installed in two-layer soil structures, the surface layer soil resistivity is different with the resistivity of the soil contacted with the grounding electrodes. The design of large-sized grounding systems is fundamentally based on assuring safety from dangerous voltages within a grounding grid area. The performance of the grounding system is evaluated by tolerable touch and step voltages. Since the floor surface conditions near equipment to be grounded are changed after a grounding system has been constructed, it may be difficult to determine the tolerable touch and step voltage criteria. In this paper, to propose an accurate and convenient method for evaluating the protective performance of grounding systems, the propriety of the method for evaluating the current flowing through the human body around on a counterpoise buried in two-layer soils is presented. As a result, it is reasonable that the grounding system performance would be evaluated by measuring and analyzing the current flowing through the human body based on dangerous voltages such as the touch or step voltages and the contact resistance between the ground surface and feet.

• Korean Journal of Human Ecology
• /
• v.9 no.4
• /
• pp.55-66
• /
• 2006

The purpose of this study was to identify the effect on the evaluation or a female teachers' role-performance based on appearance according to backgrounds of students and their parents. For this study, data was collected between October 19 and 29, 2005 by means of a questionnaire designed to gauge a subject's evaluation of a teacher's abilities in learning guidance, living guidance, and human relations. The researchers selected two middle schools and four high schools in the city of Gwang-ju. The 398 surveys completed were analyzed using factor analysis, one-way ANOVA, Duncan's multiple range test, t-test and descriptive statistics. According to the study, the evaluation of a female teacher's abilities varies with the backgrounds of both students and their parents. Among the students tested perceptions were affected by gender, grade level and type of school attended. For mothers there were differences based on age, occupation and family income.

• Journal of Internet Computing and Services
• /
• v.22 no.3
• /
• pp.9-16
• /
• 2021

This study aims to develop a human activity recognition (HAR) system as a Deep-Learning (DL) classification model, distinguishing various human activities. We solely rely on the signals from a wristband accelerometer worn by a person for the user's convenience. 3-axis sequential acceleration signal data are gathered within a predefined time-window-slice, and they are used as input to the classification system. We are particularly interested in developing a Deep-Learning model that can outperform conventional machine learning classification performance. A total of 13 activities based on the laboratory experiments' data are used for the initial performance comparison. We have improved classification performance using the Convolutional Neural Network (CNN) combined with an auto-encoder feature reduction and parameter tuning. With various publically available HAR datasets, we could also achieve significant improvement in HAR classification. Our CNN model is also compared against Recurrent-Neural-Network(RNN) with Long Short-Term Memory(LSTM) to demonstrate its superiority. Noticeably, our model could distinguish both general activities and near-identical activities such as sitting down on the chair and floor, with almost perfect classification accuracy.

• Journal of the Ergonomics Society of Korea
• /
• v.18 no.3
• /
• pp.141-152
• /
• 1999

In this paper, We performed the human body dynamic modelling for the realistic animation based on the dynamical behavior of human body, and designed controller for the effective control of complicate human dynamic model. The human body was simplified as a rigid body which consists of 18 actuated degrees of freedom for the real time computation. Complex human kinematic mechanism was regarded as a composition of 6 serial kinematic chains : left arm, right arm, support leg, free leg, body, and head. Based on the this kinematic analysis, dynamic model of human body was determined using Newton-Euler formulation recursively. The balance controller was designed in order to control the nonlinear dynamics model of human body. The effectiveness of designed controller was examined by the graphical simulation of human walking motion. The simulation results were compared with the model base control results. And it was demonstrated that, the balance controller showed better performance in mimicking the dynamic motion of human walking.

• Nuclear Engineering and Technology
• /
• v.53 no.10
• /
• pp.3460-3463
• /
• 2021

Present computing power and enhanced technology is progressing at a dramatic rate. These systems can unravel complex issues, assess and control processes, learn, and-in many cases-fully automate production. There is no doubt that technological advancement is improving many aspects of life, changing the landscape of virtually all industries and enhancing production beyond what was thought possible. However, the human is still a part of these systems. Consequently, as the advancement of systems transpires, the role of humans within those systems will unavoidably continue to adapt as well. Due to the human tendency for error, this technological advancement should compel a persistent emphasis on human error reduction as part of maximizing system efficiency and safety-especially in the context of the nuclear industry. Within this context, as new systems are designed and the role of the human is transformed, human error should be targeted for a significant decrease relative to predecessor systems and an equivalent increase in system stability and safety. This article contends that optimizing the roles of humans and machines in the design and implementation of new types of automation in nuclear facility systems should involve human error reduction without ignoring the essential importance of human interaction within those systems.

• Journal of the Korean Society of Safety
• /
• v.28 no.1
• /
• pp.117-124
• /
• 2013

Emergency operating procedures(EOPs) of nuclear power plants should be described considering the cognitive capability and limitation of operators and provide appropriate information in the aspect of human factors. Procedures which doesn't consider cognitive characteristics of operators can become causes of human errors. In previous researches, in order to reduce these problems related to the description of EOP, an improvement suggestion for EOP writer's guide has been proposed, which is reflected human factors aspects that should be considered when describing EOPs. The proposed items, however, have a necessity to be validated because it was listed from various documents such as standards and guidelines without any special validation process. For that reason, in this study, a validation process were performed to show that procedures, which are described in compliance with the requirement items proposed in the improved EOP writer's guide, have positive effects in the aspects of human errors and performance comparing with previous procedures. Experiments were performed to compare the performances of two tasks which are described in compliance with each writer's guide of before and after the improvement During each task was performed in experiments, changes of physiological responses such as EEG and ECG were measured to evaluate the cognitive workload and the stress of operators in each task. And also, as the performance, frequencies of errors and cognition speeds of each task were evaluated. In the results of the experiment, the portions of the ${\beta}$ wave decreased in the tasks overall after the improvement. In the case of ECG, change rates of the mean of R-R interval were decreased in the tasks after improvement. In the results of the performance, the cognition and the response time of the tasks after the improvement were predominant with statistical significancies. Error times in the tasks after improvement were decreased or same to the tasks before improvement. Conclusively, it was validated that the procedures were described in compliance with the improved EOP writer's guide had effects on the reduction of human errors and improvement of performance.