• Journal of the Ergonomics Society of Korea
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• v.32 no.3
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• pp.279-291
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• 2013

Objective: The aim of this study was to compare old standard EN 954-1 and new standard EN ISO 13849-1 through case study and provide necessity of adaptation of EN ISO 13849-1 in Korea. Background: International and EU harmonized standard EN ISO 13849 "safety of machinery - Safety-related parts of control system" is classified into Part 1: General principles for design and Part 2: Validation. EN ISO 13849-1 standard was introduced in Official Journal of the European Union on September 8, 2009 as harmonized standard, and old standard EN 954-1 was withdrawn on December 31, 2011. So, EU decided to use of EN ISO 13849-1 standard forcibly from January 1, 2012 for safety of machinery. New machines need to be CE marked if they are to be placed on the market in the European Economic Area(EEA), Switzerland or Turkey, and Korean machine builder should apply EN ISO 3849-1 standard for safety of machinery accordingly. However, current Korean Safety Certification system(KCs mark) for dangerous machinery is not referred to EN ISO 13849-1 standard as safety standard. There is a need of research for adaptation of EN ISO 13849-1 standard in Korea as safety standards for new design of safety-related control system which use mostly electronic components. Method: Five case studies of representative designs for safety-related control system in accordance with EN 954-1were selected according to safety category from B to 4. And these five representative designs were tried to change new design in accordance with EN ISO 13849-1 standard. The results of comparison were analyzed in aspect of economy and technical complexity. Results: The results showed that EN ISO 13849-1 provided quantitative method of application and it enabled designers to create safety-related control systems that require fewer components and less wiring, with many of the components being to a lower specification and, therefore, less costly. Conclusion: EN ISO 13849-1 standard is good for electronic safety-related control systems compare to EN 954-1. By considering the importance of application of EN ISO 13849-1 and benefits, the application of EN ISO 13849-1 as safety standard for safety of machinery is urgent in Korea. Application: The results of comparing EN 954-1 and EN ISO 13849-1 standard might help to determine the adaptation of EN ISO 13849-1 standard for safety of industrial machinery in Korea.

• Journal of the Ergonomics Society of Korea
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• v.27 no.4
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• pp.27-35
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• 2008

Recently, many studies have reported the fact that an excessively accumulated psychological and physical burden induced from physical labor conducted routinely in home and industry can be one of main reasons of musculoskeletal disorders in the working population. This fact makes increase interests in studies to reduce a risk of musculoskeletal disorders through grafting ergonomic considerations on working environment. However, there are currently limited methodologies in quantitative evaluations of new ergonomic suggestions to reduce a risk of musculoskeletal disorders. The current study is therefore performed to evaluate quantitatively effects of a design of washing machine as a new ergonomic suggestion onto prevention of musculoskeletal disorders, through application of a biomechanical evaluation methodology. For this, three-dimensional motion analysis by using musculoskeletal models with Rapid Entire Body Assessment (REBA), which has been generally used for a simple evaluation of a degree of harmfulness of the human body at specific working postures to be considered, was performed. The results of REBA did not give us enough information and their results were somewhat simple and inaccurate, but the results of the three-dimensional motion analysis give us enough information such as alteration of main muscle forces and joint moments required during washing work. All results showed that the main muscle strengths and joint moments were decreased effectively for reduction of a risk of musculoskeletal disorders during the washing work with newly designed washing machine evaluated in the current study, compared with those generated during the washing work with general washing machine. From these results, it can be concluded that a risk of the musculoskeletal disorders, which may be induced by a repetitive washing work, may be reduced through using the washing machine designed ergonomically and newly. Also, it is thought that if our ergonomic design can be applied for improvement of working environment in lifting and laying works conducted repeatedly for a treatment work of goods, which have a strong resemblance to the behaviors generated frequently during the washing work, a possibility of occurrence of the musculoskeletal disorders by the lifting and laying works may be reduced highly.

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.214-218
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• 1995

A lot of design guidelines have been proposed for menu-drive interfaces, but they are applicable only to the menus on ordinary CRT displays. Many hardware products, however, cannot employ large displays because of the cost and space limitations. Instead, a single-line display menu (SDM) is widely used, and the designers need useful guidelines applicable to the SDM. A focus is often placed upon the optimal menu structure, but only the standard menu structures, such as $64^{\1}, 8^{\2}, 4^{\3}, and 2^{\6}$, are tested for optimality. In many cases, however, ill defined or asymmetric structures are suggested as design alternatives. To determine the optimal menu structure, user performance should be obtained in terms of quantitative measures for each of the optional structures considered. Hence, a model is needed to provide a predicted value of user performance for a given menu structure. Although severaal models have been proposed for ordinary menus, none is available for the SDM yet. A performance model was developed in this study using the neural network approach. A The model developed in this study is capable of providing quantiative measures of human performance for any menu structures without conducting additional experiments, which will save much time and reduce the design cost.

• Journal of the Ergonomics Society of Korea
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• v.33 no.4
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• pp.267-279
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• 2014

Objective: The objective of this study was to define the Dynamic Sitting (DS) through trend analysis and research on the Dynamic Chair (DC) and applied technologies. Background: The effects of changing posture on the human body have been studied to find out healthy sitting postures. It is believed that changing posture is effective in reducing disc pressure on spinal cord and preventing back pain and musculoskeletal disease. But, the definition of DS and trends of DC have not been researched yet. Therefore, trend analysis of DC and its applied technologies are required to define dynamic sitting posture. Method: We researched the type of occupant postures from previous studies. And then, sitting behaviors were classified into three types; (1) sitting and standing, (2) working and studying, (3) taking a rest. Results: Variety shapes of DC and applied technologies were found out. From the result, the trend of DC and applied technology were summarized from three perspectives. ; (1) changing the chair functions according to user's intention, (2) conversion of dynamic chair technologies to office chair mechanism, (3) enables the user to change their sitting posture without operating control device. Conclusion: From this study, we defined dynamic sitting posture and analyzed the trend of DC and its applied technologies. This result might be used to develop an office chair for healthy sitting. But further investigation is required to figure out the technologies and functions for development of healthy chair. Application: The results of the publishing trend analysis might help to determine design concept of office chair.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.237-245
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• 2012

Objective: The aim of the study is to analyze female adult's body shape characteristics and to provide the basic information for clothing manufacturing. Background: The comparative study among the age groups is very fundamental to understand the body characteristics of each subjects group. Therefore, comparison of body measurements in age groups was applied in this study. Method: The study was fulfilled by the comparison between the data of the $5^{th}$ Anthropometry of Size Korea (2004) and the $6^{th}$ Anthropometry of Size Korea(2010). The subjects were 2,213 female adults aged 20~59 of the 5th Size Korea anthropometric survey and 2,025 female adults aged 20~59 of the 6th Size Korea anthropometric survey. Results: The differences indicated the decreased values in widths, depths, girths regarding the torso region and BMI. "Head height to Stature ratio" decreased significantly in the 6th data, on the other hand, "Crotch height to Stature ratio" increased in the 6th data. Through the distribution characteristic of the age groups by Stature groups, it was convinced that 160cm stature group is the most frequent among all age groups of the 6th Size Korea. Conclusion: As a summary, the meaningful differences were showed between the 5th anthropometric data and the 6th data. According to the 6th Size Korea, the distribution tendency of obesity is very similar to the 5th Size Korea data. But the percentage of obese women declined significantly. Application: These findings from the study can be utilized women's wear design and construction that reflect body characteristics.

• Journal of the Ergonomics Society of Korea
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• v.31 no.1
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• pp.247-254
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• 2012

Objective: The objective of the study is to analyze adult men's somatotype characteristics, age range from 20s to 50s comparing the direct anthropometric measurement values and to provide the basis information for developing clothing patterns. Background: The comparative study among the age groups is very fundamental to understand the body characteristics of each subjects group. Therefore, comparison of body measurements in age groups was applied in this study. Method: The anthropometric data from the $5^{th}$ Anthropometry of Size Korea(2004) and $6^{th}$ Anthropometry of Size Korea(2010) were applied for the data analysis. Results: As a result, the chest depth/chest width index(the value of chest depth divided by chest width) was increased and the waist depth/waist width index was decreased in all age groups. In addition, the hip depth/hip width index was decreased in age of 20's and 50's. This means that the chest width and hip width were decreased and the waist width were increased. From the data of the 5th Size Korea, the obese men(BMI: 25~30) in the 50s showed the highest percentage of 47.1%, and 44.8% of obese men(BMI: 25~30) in the 40s recorded the highest rate base on the data of the 6th Size Korea. Conclusion: It is concluded that the some differences were showed between the 5th anthropometric data and the 6th data. In particular, obesity tendencies of men in their 20's and 30's were observed significantly compared to other age groups. Application: These findings from the study can be utilized men's wear design and construction that reflect body characteristics.

• Journal of the Ergonomics Society of Korea
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• v.24 no.3
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• pp.11-27
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• 2005

The objectives of this study are to analyze representative wrist postures while using hand tools and parts at general assembly processes, to evaluate perceived discomfort on the wrist when external loads are present, and to suggest an evaluation and prediction model of perceived discomfort. Sixteen subjects participated in an experiment to appraise perceived discomfort. Three types of the wrist postures with five levels of non-neutralities were analyzed when five levels of external load were applied to each posture. The ANOVA results showed that the perceived discomfort of wrist postures was significantly affected by both the wrist posture and external load (p$<$0.001). It was also shown that some of the interactions between external loads and the wrist postures(Flexion/$Extension^*$Load, Flexion/$Extension^*$supination/pronation, ulnar/radial $deviation^*$supination/pronation) were significant(p$<$0.001). The result implies that a new posture classification scheme for workload assessment methods may be needed to reflect such effects of external load and wrist posture. A regression model of perceived discomfort was developed with respect to wrist posture and external load from the experimental data. A subsequent experiment revealed that the correlation coefficient between the predicted values of perceived discomfort from the model and the actual values obtained from the experiment was about 0.98. It is expected that the results help to properly estimate the body stress resulting from worker's postures and external loads and can be used as a valuable design guideline to analyze potential hazard of musculoskeletal diseases in industry.

• Journal of the Ergonomics Society of Korea
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• v.35 no.4
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• pp.193-204
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• 2016

Objective: This study carried out base research to build an agricultural safety monitoring system through ICT convergence to reduce safety accidents and enhance welfare in life in the agricultural field. Background: The functions and values of rural villages as the space of living are recognized anew, but occupational accident rate due to farm work accidents is on the rise each year. Therefore, the seriousness of such a problem emerges. The convergence technology combining ICT is recently applied to industries overall, and therefore better services are offered. However, studies on ICT convergence has not yet been applied to the agricultural safety field. Method: This study identified ICT convergence service technology trends and representative serious accident types mainly occurring in agricultural activities. This study defined the major factors of farm work accidents and ICT to solve those accident factors including the sensor technology, wired/wireless communication technology and location information service, and applied them to prototype PCB for the development of an agricultural safety monitoring system. Results: This study proposed an emergency monitoring system for farmers and a harmful environment monitoring system. The ICT technology to prevent farm work accidents can be summarized as sensing technology, ICT and network technology and user interface technology. This study also designed PCB module configuration and situation judgment algorithm as basic research for proposed monitoring system development. Conclusion: The ICT-based agricultural safety monitoring research proposed in this study is expected to become the basis to build a future real time monitoring system, and also is expected to contribute to social safety and welfare service improvement for farmers. Application: The ICT convergence farmer accident prevention system will make contributions to the prevention of serious farm work accidents.

• Journal of the Ergonomics Society of Korea
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• v.30 no.2
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• pp.311-317
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• 2011

Objective: The present study was intended to identify (1) the intra- and inter-rater reliabilities of a visual sensibility evaluation protocol and (2) the effects of NaCOC color and scouring method on the visual sensibility of NaCOC. Thirty female participants(20s & 30s) were participated in the visual sensibility evaluation of NaCOC. Background: Interests in naturally colored organic cotton(NaCOC) increase rapidly in parallel with the social trend of eco-friendly living and wellbeing. Method: Three color sets (ivory, green, and coyote-brown) of NaCOC specimens including one untreated and four treated specimens($Na_2CO_3$; NaOH; enzyme; boiling water) were examined in the study. The visual sensibility evaluation was conducted by the test-retest method using nine pairs of bipolar visual sensibility adjectives(bright-dark; clear-murky; heavy-light; vivid-subdued; warm-cool; fresh-stale; strong-weak; showy-plain; and luxurious-cheap). Results: As a result of reliability of a visual sensibility evaluation protocol, inter-rater variability(average SD=1.06) of visual sensibility evaluation was more than 1.4 times the intra-rater variability(average SD=0.74). However, both the sensibility evaluation reliabilities did not show any systematic pattern of changes. Lastly, ANOVA and post-hoc analysis showed that preferred scouring methods for a visual sensibility adjective pair significantly vary depending on NaCOC color. Application: Both the reliability of visual sensibility evaluation protocol and the analysis of proper scoring method of NaCOC in the study would be useful information to design the affective textile.

• Journal of the Ergonomics Society of Korea
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• v.31 no.5
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• pp.629-636
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• 2012

Objective: The purpose of this study is to compare the characteristics of single and double finger gestures related on the web browser and to extract the appropriate finger gestures. Background: As electronic equipment emphasizes miniaturization for improving portability various interfaces are being developed as input devices. Electronic devices are made smaller, the gesture recognition technology using the touch-based interface is favored for easy editing. In addition, user focus primarily on the simplicity of intuitive interfaces which propels further research of gesture based interfaces. In particular, the fingers in these intuitive interfaces are simple and fast which are users friendly. Recently, the single and double finger gestures are becoming more popular so more applications for these gestures are being developed. However, systems and software that employ such finger gesture lack consistency in addition to having unclear standard and guideline development. Method: In order to learn the application of these gestures, we performed the sketch map method which happens to be a method for memory elicitation. In addition, we used the MIMA(Meaning in Mediated Action) method to evaluate gesture interface. Results: This study created appropriate gestures for intuitive judgment. We conducted a usability test which consisted of single and double finger gestures. The results showed that double finger gestures had less performance time faster than single finger gestures. Single finger gestures are a wide satisfaction difference between similar type and difference type. That is, single finger gestures can judge intuitively in a similar type but it is difficult to associate functions in difference type. Conclusion: This study was found that double finger gesture was effective to associate functions for web navigations. Especially, this double finger gesture could be effective on associating complex forms such as curve shaped gestures. Application: This study aimed to facilitate the design products which utilized finger and hand gestures.