• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.87-96
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• 2013

Objective: The aim of this study is to describe several issues which should be considered in the human reliability analysis of soft control operations in nuclear power plants. Background: The operational environment of advanced main control rooms is totally different from that of conventional control rooms. The soft control is one of the major distinguishable features of the advanced main control rooms. The soft control operations should be analyzed to estimate the effects on human reliability. Method: The literatures, about task analysis, simulation data analysis, and a human reliability analysis method for the soft control, were reviewed. From the review, important issues for the human reliability analysis of the soft control were raised. Results: The results of task and simulation data analysis showed that the soft control characteristics could have large effect on human reliability and they should be considered in the human reliability analysis of the soft control operations. Conclusion: The soft control may affect human error and performance of operators. The issues described in this paper should be considered in the human reliability method for the advanced main control rooms. Application: The results of the soft control operation analysis might help to design more efficient interface and education/training program for preventing human errors. The described issues might help to develop a human reliability analysis method for soft control operations.

• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.37-45
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• 2013

Objective: This study describes the change of operator performance in drastic change of illumination level, and proposes an alternative method to cope with it. Background: The control standard of illumination for nuclear power plants(NPPs) is based on the set of limit criteria for maintaining a specific illumination level. However, there is a possibility to cause human errors according to the psychological and physiological influences to operators in the situation of drastic change of illumination such as SBO(Station Black Out), so a basic study is necessary to review the current approach. Method: We assessed the visual fatigue, subjective work load and task performance according to the three illumination situations(Normal Illumination, Emergency Illumination, and Drastic Change of Illumination). Result: Research finding shows that there are not significant differences in task performance between normal illumination (1,000lx level) and emergency illumination (100lx level), only if beyond the dark adaptation limit. However, subjective work load on mental demand and visual fatigue show a potential challenge to visual performance in drastic change of illumination. Conclusion/Application: Several trials can complement this challenge in NPPs by applying 3-way communication, enhancing readability of procedures, and managing the visual factors affecting the operators' performance through a Visual Environment Management Program including visual health aspects, etc.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.563-568
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• 2010

TV businesses that have brought a competitive structure in terms of price, definition, product design for a long time now are bringing User eXperience (UX) into relief as DTVs come to support broadcast information-related services such as various broadcast channels and Electronic Program Guide(EPG), etc., and playing of multimedia contents like music/videos, etc. This study worked on an evaluation by developing a UI to control easily the various and complex broadcast contents or multimedia contents provided by DTVs. The UI Design for new DTVs was developed based on Function, Flow and Form in the concept of Single ABC (Access, Browser and Control), and the usability test of the developed UI concept along with the UIs of the major DTV products, was done for Channel Managers and the multimedia browsers for 32 users of DTVs in the U.K./U.S., respectively. As a result of the usability test, the new concept of Channel Manager was evaluated high both in the U.K./U.S, while the multimedia browser was evaluated low in the U.S., relatively.

• Journal of the Ergonomics Society of Korea
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• v.29 no.4
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• pp.505-511
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• 2010

The purpose of this study was to show the occurrences of musculoskeletal disease in aging society and basic information on developments of a systematic prevention program and proposed management measures needed to prevent the disease. The Korea Occupational Safety & Health Agency has analyzed cases of industrial accidents that cause musculoskeletal disease, from 1998 to 2007. They found 30,439 people suffering from the disease during those ten years. This information is from the Ministry of Labor's industrial accident analysis and the industrial accident survey from the Korea Occupational Safety & Health Agency. The data was analyzed by age and industrial classification. In Korea, according to the studies on aging society, the occurrence of musculoskeletal disease in elderly employee's have increased, so prevention programs are needed. Psychological, mental and cognitive programs are needed, as well as other prevention programs to ensure health in old age. In this study, we were able to see the state of musculoskeletal disease in aging society and the countermeasures to prevent the disease, such as a universal design, guarantees, and recuperation services. Later, we found that studying the various elderly patients would be of great help to us.

• Journal of the Ergonomics Society of Korea
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• v.33 no.6
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• pp.515-532
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• 2014

Objective: The purpose of this study is to define consumers' affection on the interior design of commercial cars in terms of its design factors: color, embossing and gloss as independent factors. Background: Existing affective studies related to interior of vehicle focus on just sedans. However, there is no affective study about the interior of commercial cars. In addition, it is hard to change levels to which manufactures want. Method: Representative design factors were drawn using ANOVA and SNK analysis and definitive affective vocabularies were drawn using factor analysis. Furthermore, the results of 3D experiment were analyzed using ANOVA and LSD analysis. 3D images for the experiment were made using 3D max program. The experiment revealed that consumers discerned the differences in levels of each design factor and affective vocabulary. Results: The ANOVA revealed that beige color "A" type and non-gloss were the most preferred design in terms of the affective vocabularies and total preference. Conclusion: The result of the experiment may help manufactures to design the interior of commercial cars in the near future. Furthermore, the ANOVA result of affective vocabularies evaluation is expected to suggest a meaningful guideline. Application: The study results may be utilized as a guideline for interior design of commercial cars.

• Journal of the Ergonomics Society of Korea
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• v.36 no.1
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• pp.53-67
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• 2017

Objective: The purpose of this study is to build basic data to systematically develop a hand function evaluation tool by determining the effects of age, gender and target force level on the difference in hand function according to the target force level. Background: Precise and objective evaluation of hand functionality is a very important factor in quantifying treatment progress in patients or elderly people, and in verifying treatment effects. However, most hand function evaluations lack objectivity and accuracy, and therefore it is difficult to properly treat patients according to the given situation. Method: Sixteen healthy subjects (eight elderly and eight young people) participated in this study to evaluate the effects of age, gender, and target force level on tracking performance through rRMSE in terms of the tracking force and actual exerted force, by carrying out a task of maintaining six different target force levels for 20 seconds. Results: The result of this experiment indicated that elderly people and women had a lower ability to maintain a certain level of force than young people and men by 16% and 10%, respectively. The target force level results showed that the tracking error of the lowest force level (5% MVC) was significantly higher than that of 15% MVC, which in turn showed a higher tracking error than that of the higher target force levels. Conclusion: The results of this study can thus be utilized to develop a rehabilitation program for elderly people or other patients. Application: The authors expect that the results of the present study will be valuable to develop a rehabilitation program and hand function evaluation tool.

• Journal of the Ergonomics Society of Korea
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• v.23 no.2
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• pp.55-80
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• 2004

Multichannel on digital TV not only gave opportunities to the TV audience to view a wide range of programs. but also made it difficult for them to search for the program which they plan to view among over 1000 programs broadcasted on more than 100 channels. In this paper the functions of EPG (Electronic Program Guides) required by the users on digital TV were derived from the systematic analysis of multichannel viewing situations. In the situation analysis the situations where they viewed programs on more than 100 channels were generated systematically and the viewing processes in those situations were analyzed to identify user needs and derive the required functions of EPG. We surveyed the viewing behavior of the audience who subscribed to a digital satellite broadcast. SkyPerfecTV. in Tokyo. Japan. The purpose of the survey was to verify the validity of the functions derived from the situation analysis and to identify hidden user needs which were difficult to in the situation analysis. The functions were implemented on a working prototype of EPG based on a digital TV simulator which broadcasts 500 programs on 100 channels and can be controlled by three working prototypes of personal remote controllers. The working prototype will be used in Participatory Design to make it possible for the users to experience and verify the usefulness of the required functions of EPG and also find problems in user interface design of EPG

• Journal of the Ergonomics Society of Korea
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• v.17 no.3
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• pp.13-22
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• 1998

Aircraft and the three-dimensional environment in which they operate are not user-friendly for human beings. As a result, maintaining the proficiencies necessary to safely and efficiently fly an airplane are difficult, and costly. The physiological and emotional status of the human element remains crucial in maintaining safe performance by all crew members. In the study of Hagiwara et al.(1993). they called the physiological and emotional status of the human element into the human alertness or physiological activity and stress, fatigue, circadian rhythm, alcohol. smoking, and self-medication are known the major factors that deteriorate the human alertness. Accordingly. this paper deals with the quantitative and objective performance test based on tracking error and reaction time by means of the new computer test program into which the perception-motion system of human beings is applied. Throughout this experiment using performance test, the results suggest that performance capability in state of sleep deprivation 2 hours and alcoholic 0.05~0.06% in blood were more impaired than one in a normal state, and they further showed statistically significant differences between them, which were influenced by impairment factors of body regulation and pilot's grade. We also obtained the prediction value and the 95% confidence interval of tracking error and reaction time at the normal state for the purpose of distinguishing performance capability between the normal state and the abnormal state. And it is expected that the evaluation of human alertness using performance test will be applied to the quantitative assessment of an each pilot's realistic consciousness/attention, and will lead a flight commander to the accurate decision of mission approval prior to a flight.

• Journal of the Ergonomics Society of Korea
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• v.29 no.2
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• pp.203-210
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• 2010

For the development of a better product which fits to the target user population, physical workloads such as reach and visibility are evaluated using digital human simulation in the early stage of product development; however, ergonomic workload assessment mainly relies on visual observation of reach envelopes and view cones generated in a 3D graphic environment. The present study developed a quantitative assessment method of physical workload in a digital environment and applied to the evaluation of a Korean utility helicopter (KUH) cockpit design. The proposed assessment method quantified physical workloads for the target user population by applying a 3-step process and identified design features requiring improvement based on the quantified workload evaluation. The scores of physical workloads were quantified in terms of posture, reach, visibility, and clearance, and 5-point scales were defined for the evaluation measures by referring to existing studies. The postures of digital humanoids for a given task were estimated to have the minimal score of postural workload by finding all feasible postures that satisfy task constraints such as a contact between the tip of the index finger and a target point. The proposed assessment method was applied to evaluate the KUH cockpit design in the preliminary design stage and identified design features requiring improvement. The proposed assessment method can be utilized to ergonomic evaluation of product designs using digital human simulation.

• Journal of the Ergonomics Society of Korea
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• v.6 no.2
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• pp.19-28
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• 1987

If an error occurs in the automatic mode when the advanced teleoperator system performs a task in hostile environment, then the mode changes into the manual mode. The operation by program and the operation by hyman recover the error in the manual mode. The system resumew the automatic mode and continues the given task. In order to utilize the inverse kinematics as means of the operation by program in the manual mode, Lee and Nagamachi determined the end point of the robot trajectory planning which varied with the height of the task object recognized by a T.V monitor, solved the end point by the fuzzy set theory, and controlled the position of the robot hand by the inverse kinematics and the posture of the robot hand by the operation by human. But the operation by human did take a lot of task time because the position and the posture of the robot hand were separately controlled. To reduce the task time by human, this paper developes an error recovery expert system (ERES). The position of the robot hand is controlled by the inverse kinematics of the cartesian coordinate system to the end point which is deter- mined by the fuzzy set theory. The posture of the robot hand is controlled by the modulality of the robot hand's motion which is made by the posture of the task object. The knowledge base and the inference engine of the ERES is developed using the muLISP-86 language. The experimental results show that the average task time by human the ERES which was performed by the integration of the position and the posture control of the robot hand is shorter than that of the research, done by the preliminary experiment, which was performed by the separation of the position and the posture control of the robot hand. A further study is likely to research into an even more intelligent robot system control usint a superimposed display and digitizer which can present two-dimensional coordinate of the work space for the convenience of human interaction.