• Journal of the Ergonomics Society of Korea
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• v.32 no.1
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• pp.145-152
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• 2013

Objective: The aim of this study is to develop an ergonomic office chair that has an alarm function for the unbalanced sitting postures. Background: Contrary to expectation, it is reported that office workers sit on their chairs much more in unbalanced postures during daily work. Even though an office worker uses an ergonomically good-designed chair and begins their work in a good sitting posture, his/her posture is likely to shift to the unbalanced bad posture. Therefore, a posture alarm system would be very helpful in keeping office workers' good postures. Method: We developed a prototype chair with four load cells under a seat pan and one load cell beneath a backrest. Through some experiments, we set the criteria for unbalanced bad postures then implemented the criteria into the alarm system of the prototype chair. The chair called e-BASE chair could detect unbalance postures and show alarms for chair users. We also enhanced back support by developing a step-wised folding backrest. Results: The e-BASE chair showed better performance in interface pressure distributions and balanced posture ratio in VDT work. Conclusion: The ergonomic chair with posture alarm function(e-BASE chair) was developed. It showed better performance in seat pressure distribution and in keeping good posture during office work. Application: The posture alarm system and folding backrest can be applied to the new models of office chair.

• Journal of the Ergonomics Society of Korea
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• v.11 no.1
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• pp.103-109
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• 1992

Direct manipulations are composed of pointing operations and dragging operations. In order to find the optimum design parameters (such as C/D ratio, moving direction) for the direct manipulation of a GUI(Graphical User Interface), an ergonomic experiment was devised (2*4*3*8 design) to measure the performance of a mouse (Microsoft) and a trackball (Logitech). The results showed that the mouse was more suitable for the direct manipulation (expecially for the dragging operation) than the trackball, and the suitable C/D ratio was 10 (for the mouse) and 16 (for the trackball). Also the movement direction was a determinant factor in trackball performance.

• Archives of design research
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• v.14
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• pp.1-7
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• 1996

Designers often hesitate to decide the shape, size, and layout of a product. Though ergonomic principles and data are absolutely needed in this process, they don have enough guidelines to refer. For the refrigerator designers, they also are not convinced of their decision: the vertical position of the freezing and refrigerating rooms, the height of shelves, the shape of door-handle, etc. To support the refrigerator design, we applied several ergonomic methods to the evaluation of refrigerator. EMG was measured to evaluate the load of users lumbar muscle. Based upon the experimental EMG data, we developed a model to estimate the relative load corresponding to the height of refrigerator shelves. Two different layouts of a refrigerator, R/F and F/R styles, were compared with the model. A three-dimensional motion analysis method was used to evaluate the users motion of using a refrigerator. Ten door-handles with the different shapes and positions were evaluated by tracking the rotations of the users arm. Video protocol analysis was used to evaluate the user interface of a control panel in a refrigerator. Finally, we suggested several ergonomic design guidelines based on the facts found in this research and the anthropometric data of the Korean adults. The results of this study can be applied to the ergonomic design of refrigerators

• Journal of the Ergonomics Society of Korea
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• v.35 no.6
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• pp.595-609
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• 2016

Objective: The purpose of this study was to develop and validate the guidelines for Medic Work Table (MWT) based on the anthropometric data of medical technologists. Background: Users' anthropometric data such as sitting height, sitting elbow height, knee height, and so on are significant factors for designing comfortable and useful furniture. Thus, many guidelines for different types of desks and chairs based on the users' anthropometric data have been suggested to many researchers. However, few researches have been conducted to provide design guidelines for MWT for blood collecting task. Medical technologists often use their upper extremities to perform blood collecting task with high repetitions. These repeated motions could be a critical factor in the prevalence rate of Work-related Musculoskeletal Disorders (WMSDs). Therefore, a study on ergonomic design of MWT would be essential in preventing the WMSDs and improving the quality of the working environment of medical technologists. Method: This study suggested design guidelines for ergonomic MWT by focusing on the heights of the upper side and underside, depths of the inside and outside, and width of MWT through anthropometric studies and literature reviews. Afterwards, a new MWT was made using the suggested design guidelines for this study. Five healthy medical technologists participated to evaluate the original MWT and new MWT. All participants took part in the range of motion (ROM) test, electromyography (EMG) muscle activity test, and usability test to validate the suggested guidelines in this study. EMG signals of related muscles (Flexor Carpi Ulnaris, Extensor Carpi Ulnaris, Deltoid Anterior, and Biceps Branchii) were recorded through the surface electromyography system from both the original MWT and the new MWT. The ROM test of the shoulder and elbow flexion was also assessed using motion sensors. Results: The newly designed MWT showed decreased ROMs of the shoulder and elbow up to 22% and 18% compared to the original MWT. The muscle activities in the new MWT also showed a decrease of 13% in Anterior Deltoid, 6% in Biceps Brachii, 5% in Flexor Carpi Ulnaris, and 8% in Extensor Carpi Ulnaris muscle groups, compared to the original MWT. In the usability test, the satisfaction score of the new MWT was also 56.1% higher than that of the original MWT. Conclusion: This study suggested guidelines for designing MWT and validating the guidelines through qualitative and quantitative analyses. The results of motion analysis, muscle activity, and usability tests demonstrated that the newly designed MWT may lead to less physical stress, less awkward posture, and better physical user interface. Application: The recommended guidelines of the MWT would be helpful information for designing an ergonomic MWT that reduces physical loads and improves the performance of many medical technologists.

• Journal of the Ergonomics Society of Korea
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• v.29 no.5
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• pp.771-782
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• 2010

Today, the number of elderly drivers who use navigation is increasing with the growing number of elderly drivers. The purpose of this study is to provide guidelines on the interface of car navigation for elderly users. To extract significant factors which were distinguished between young and elderly users, both young and elderly users executed the driving test by installing two car navigation alternatives. The analysis was conducted through t-test. The results show that significantly different factors were the number and the meaning of the menu items in the initial screen, the location and the meaning of the menu icons in the map screen, the ease of search of the menu and the text size in the menu screen. Improvements for the factors of the initial screen and map screen were made with reference to ergonomic guidelines, and suggested through experiments comparing design alternatives for the menu screen. Design alternatives were made through a combination of investigative variables, and the analysis was conducted through ANOVA. The results show that Alternative 7 (the location of the tab was placed at the bottom, menu representation was done with the text font size of 18pt and the location of menu navigation icons was shown at the upper left) was preferred in terms of user's preference and the execution time. So if the suggested menu for elderly users are added to the existing design, both users will satisfy their desires. The guidelines suggested in this study will help the designer of car navigation take elderly users into consideration.

• Korean Institute of Interior Design Journal
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• v.19 no.6
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• pp.249-256
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• 2010

For guaranteeing for security of nuclear power plant, ergonomic factors have been applied to design of main control room, core area for management and control of nuclear power plant, but design elements for performance of operators have been ignored. As the behaviors of operators are important for security of nuclear power plant, space design which makes them pleasant psychologically and makes them maintain attention on security equipments ceaselessly is required. Therefore, the purpose of this study is to analyze space characteristics of main control rooms according to regulations of nuclear power plant and general guidelines of space design, and to offer basic data for designing of main control room which makes operators pleasant psychologically and physically. At first, theoretical issues related with design of main control room are reviewed and several premises of space are developed by abstracting design elements from common space and regulations of nuclear power plant and, then integrating each design elements interactively. In short, the improvement of system environment based on human-machine interface space has brought about perceptual, cognitive, and spatial changes and has realized next generation of main control rooms. And, differences and similarities between ordinary space and main control room, which ergonomic sizes and regulations are applied and is VDT environment based on LDP, are discussed in relation to 13 design elements and 17 space premise.

• Journal of the Ergonomics Society of Korea
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• v.34 no.3
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• pp.247-264
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• 2015

Objective: The purpose of this study is to determine the priority of information presentation and the effective menu type to be placed in the center of a gauge cluster display for commercial trucks and to present a set of ergonomic designs for the gauge cluster display. Background: An effective ergonomic design is specifically needed for the development of the gauge cluster display for the commercial trucks, because more diverse and heavier information is delivered to truck drivers, compared to the information to passenger car drivers. Method: First, all the information that must be shown on the commercial truck display was collected. Then, the severity, frequency of use, and display design parameters were evaluated for those information by commercial truck drivers. Next, an analysis on the information attributes and the heuristic evaluation utilizing the display design principles were carried out. According to the results, a design alternative of the main screen to be displayed was constructed by priority. A comparative analysis between the alternative and existing main screens was also conducted to see the efficacy of the designs. Lastly, we conducted an experiment for the selection of menu type. The experiment was conducted using the driving simulator with an eye-tracking device. The independent variables were four types of the menu reflecting the commercial truck characteristics such as grid type, icon type, list type, and flow type. We measured preference, total execution time, the total duration of fixation on the gauge cluster area, and the total number of fixation on the gauge cluster area as dependent variables. Results: Four types of driver convenience information and six types of driver assistance information were selected as the information to be placed primarily on the main screen of the gauge cluster. The Grid type was the most effective among the menu types. Conclusion: In this study, the information that appears on the main screen of the display, the division of the display and the design of the menu type for commercial truck drivers were suggested. Application: This study is expected to be utilized as guidelines on the ergonomic design of a gauge cluster display for commercial trucks.

• Korean Institute of Interior Design Journal
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• v.16 no.5
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• pp.81-88
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• 2007

Energy consumption has been increased world widely, and the energy retain is one of the most important economic alternatives. These tendencies expand the nuclear power plants not only quantitatively but also qualitatively. Despite of the increasing construction of nuclear power plants and related facilities, every system in main control room(MCR) has been designed and administered solely based on the safety-first principles because of the specificity of nuclear industry. However, recent main control rooms started with the concept that the operators' performance could be optimized though the organic interrelation between human, machine, and environments. Now, it has been recognised in the scope of Ergonomics and Space Design which acknowledge our living spaces as Man-Environment Interface and this change connotes the MCR spaces should be special spaces rather than ordinary spaces. This research investigated domestic and foreign nuclear power plants' MCRs to suggest basic alternatives which can be applied to future MCR. With the review of characteristics of MCR, an integration of interior design, lighting and Ergonomics was explored and classified as types. Futhermore, the classification of environmental characteristics within the relationships between human, machine, and environments was developed through the case analysis of nuclear power plants. The results of this study will provide a basis of space design for system environments that the high level of safety and function are extremely important.

• Journal of the Ergonomics Society of Korea
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• v.23 no.3
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• pp.13-24
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• 2004

Anthropometric data is a fundamental resource in developing ergonomic products and workplaces. However, designers often experience difficulty in searching anthropometric data relevant to the design due to the technicality of anthropometric terminologies, ambiguity in the description of measurement method for some anthropometric variables, and inefficiency of existing search methods for anthropometric data. The present study suggests a method to develop a classification system of anthropometric variables for systematic, efficient search of anthropometric data. The proposed method first classifies anthropometric variables according to body segment and type of variable, and then arranges anthropometric variables of the same body segment and variable type by comparing the heights of their reference points. The proposed classification method was applied to establish a classification system of 66 anthropometric variables that were selected for an automotive interior design. Then the established anthropometric classification system was utilized to design a search interface of a web-based anthropometric data retrieval system.

• Journal of the Korean Society of Marine Environment & Safety
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• v.8 no.1
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• pp.53-59
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• 2002

A correctly designed bridge offers improved operational safety in terms of increased vigilance, flexibility of operation, precision of control and operator＇s situational awareness. According1y to design human centered bridge, the consideration shall be given to the man-machine interface, location and interrelation of workstation, configuration of console, windows. field of vision and bridge working environment. The state-of-the-art suits for one-man operation by integration of conning information and central information presentation. Further, it is desirable to enable two man ship operation for emergency operations, training purposes and redundancy. In this point of view, this thesis would like to design a conceptual bridge.