• Journal of the Ergonomics Society of Korea
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• v.34 no.5
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• pp.447-454
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• 2015

Objective: The purposes of this study are to survey general and ergonomics relevant patents of major foreign countries, to classify the ergonomics patents into some categories frequently found in the patents lists surfed and to compare the results with those of Korea. Background: Under today's severe competitions between countries and between companies, the intellectual property has never been more important. It is needed to investigate Korea's positions and worldwide status of patent applications and grants for general and ergonomics patents. Method: This study was mainly based on relevant websites surfing such as KIPRIS, FPO, EPO, WIPO, etc. Results: The results showed that while Korea placed fourth in patent applications and grants in 2012, following US, Japan and China, Korea ranked seventh in the number of ergonomics patents. Of the overseas ergonomics patents, the proportion of tool/device was the second highest to category of others, followed by chair/desk, grip/handle and keyboard, etc. Compared to the overseas ergonomics patents, Korea showed a slightly different trend that there were less patents for specific fields of ergonomics such as grip/handle, keyboard, tool/device, etc. Conclusion: The number of ergonomics patents of Korea was behind most foreign countries surveyed in the number of patent applications and grants of, and there were many categories of overseas ergonomics patents. Application: This study would be used as a reference or guideline when developing varying ergonomic products or applying to ergonomics patents.

• Journal of the Ergonomics Society of Korea
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• v.31 no.3
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• pp.463-467
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• 2012

This study aims to empirically investigate population stereotype of burner-control linkage of four-stove gas range for Koreans. Background: The previous studies' results for gas range stereotypes were different depending upon methods adopted, i.e., whether using questionnaires, computer simulation or physical models. It is known that the physical model experiment should not be methodologically replaced by the computer simulation or paper-and-pencil tests. Stereotype of gas range for Koreans was surveyed based on questionnaires, but has not been dealt with by using physical models. Method: An experiment was conducted to investigate stereotype of four-burner gas range, in which 32 subjects participated and a real gas range available in the market was bought and used. Four types of burner-control linkage were used as independent variable, and reaction time as dependent variable. Results: ANOVA revealed that four types of burner-control linkage and subjects' gender were not significant on reaction time. Duncan's multiple range test showed that reaction times for type III was significantly lower than those for the other three types of burner-control linkage(${\alpha}$=0.05). Conclusion: It is concluded based on the results of this study that stereotype of gas range for Koreans is type III. This is in agreement with results of existing studies using questionnaire survey, while different from those based on physical models. Application: The results of this study would be useful as an ergonomic guideline when designing gas ranges or similar equipments for minimizing operation errors.

• Journal of Korean Institute of Industrial Engineers
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• v.26 no.2
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• pp.110-116
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• 2000

The soft drink deliveries are made for a broad line of soft drink products by using a hand truck and the backpack mode of carriage. The workers usually deliver the beverages by backpack mode of carriage, because they feel safe with such a carrying method in stairways. In this study, the physiological workload of backpack carrying was investigated, especially focused on the effects of weight of load and carrying by the stairway. A laboratory experiment was conducted to measure heart rate and oxygen uptake during backpack carrying tasks, and an ergonomic guideline was proposed for such type of task based on the results of the experiment. Eight healthy male subjects performed the backpack carrying of 40kg and 60kg, (1) on the level ground, (2) upstairs and (3) downstairs. The result showed that the stairways caused the increased physiological cost, and that a carrying load of 60kg required significantly higher physiological cost as compared to carrying 40kg. Although backpack carrying has some advantages in the biomechanical aspect, it should be advised to carry a load of less than 40kg, since the task requires a very high physiological cost. During backpack carrying, it is also recommended for a delivery person to make more trips with a light load rather than to make less trips with a heavier load at one trip.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.3
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• pp.176-182
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• 2005

American Conference of Governmental Industrial Hygienists (ACGIH) adopted the Lifting Threshold Limit Values ($TLVs^{(R)}$) in 2005 as a guideline for protecting the workers from work-related low back and shoulder disorders associated with repetitive lifting tasks. The TLVs consist of three tables with recommended weight limits for lifting tasks and their determination procedures are simple. The TLVs sans the material weight/the recommended values (LITLVs) were obtained from 45 lifting tasks in ship engine manufacturing factories. These values were compared and correlated with the Recommended Weight Limits (RWLs) and lifting indices (LIs) determined by the Revised Lifting Equation (LE) of the National Institute for Occupational Safety and Health (NIOSH). The average ratio, LITLVs/LIs, was 0.8 (LITLVs: $1.3{\pm}0.8$, LIs: $1.6{\pm}0.7$). Thus, the TLVs underestimated the risk than the LE. The LITLVs were highly correlated with LIs (r=0.82). The predicted value of LITLVs when LIs=1 wa 0.76. Using the predicted TLVs the higher risk ones of a large number of tasks can be screened to be further investigated.

• Journal of the Ergonomics Society of Korea
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• v.16 no.2
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• pp.29-38
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• 1997

The research on the factors which effect on legibility is mainly utilized as the basic data of selecting the standard guideline of VDT screen. But the research on Korean is scarcer than that of English. Furthermore, it is unreasonable to apply the results of the foreign language to Korean, beause of the difference between the typography of English and that of Korean. Therefore, more systematic and ergonomic research of the Korean typography on VDT screen is needed. In this paper, an experimental study on search speed and error rate is designed and performed according to different Korean letter size and font on search task with VDT. The experimental screen based on popular Ming and Gothic style is made up of total 12 artificial screens, each 6 different font size. As the criteria of the performance, searching speed(s.s.) and error rate (e) are selected, and CFF value is measured to evaluate user's visual fatigue. The results of experiment in font show that the Korean Gothic style is superior to the Korean Ming style in user's visual performance. The letter size that gives user the optimal performance ranges from the visual angle 39.8' to 55.5' in Ming style, from the visual angle 39.8' to 52.6' in Gothic systle. In visual fatigue experiment, the better performance of letter size is, the less tired user feels. And the smaller letter size is, the more tired user feels. There is no relationship between font and user's visual fatigue.

• Journal of the Ergonomics Society of Korea
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• v.18 no.1
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• pp.133-147
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• 1999

Traffic signs without a cognitive consideration in their design may cause information-processing problem that could result in a mental confusion among drivers often lead to a serious traffic accident. Therefore, in this study, several traffic signs currently used in Seoul Metropolitan area have been sampled and analyzed to identify design problems that usually caused by neglecting drivers cognitive ability. To classify the practical design problems, five major information-processing problems have been suggested: indistinguishable information, information conflict, missing information, sign-load mismatch, and information overload. In order to solve these cognitive problems, new traffic signs have been suggested in this study. An experiment was also performed to validate the new traffic sign. Twenty-four healthy subjects participated in the experiment. They were asked to answer the Question after observing the traffic signs continuously displayed on computer screen. The result indicated that subjects improved the accuracy in understanding the signs by 1.4 times when they used the suggested traffic sign compared to the old one. Based upon the results, a cognitive guideline was suggested for correct and speedy reading of traffic signs by improving information processing and reducing of human error. In conclusion, the traffic sign may well be applied to design an intelligent traffic sign system to increase the safety and comfort of drivers, especially in complex load condition.

• Korean Journal of Occupational Health Nursing
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• v.14 no.1
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• pp.44-55
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• 2005

Purpose: The purpose of this study was to describe the current status of work-related back pain among nurses in the U.S. Method: Literature review and website searching were conducted. Key words as 'nurse and back pain (or back injury)' were used in searching the Medline, NIOSHTIC-2and reference list of selected studies. Total studies were selected of which subjects were nurses working in the U.S., and published since 1970. Results: Though there was variation in the measurement among studies, the prevalence rate of back pain among nurses in the U.S. could be estimated about 50%. Risk factors were confirmed as the frequency of patient lifting, ward, nursing shortage, overtime, work shift, stress on physical demand, but age and work experiences showed the inconsistent relation. It has been well known that educational approach is not enough to prevent back pain. Intervention studies to apply the ergonomic approach using mechanical devices reported the effects, but the devices were less diverse than European countries or Canada. The study for lifting team was rare. Federal government developed only the guideline for nursing home that had no legal obligation. As a professional nursing organization, ANA has been trying to educate and advocate for "No lift policy" since 2003. Meanwhile, two trade unions of nurses made efforts to establish the law strengthening the responsibility of health care facilities. Conclusion: The research and policy development will be needed to prepare to rapid increase of back pain among Korean nurses.

• Journal of the Ergonomics Society of Korea
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• v.36 no.1
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• pp.9-21
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• 2017

Objective: The objective of this study is to understand the effect of angle and curvature of push-return switches, which are external factors in the operation environment inside the cars, on the feel of operation and to propose optimum alternatives. Background: Customers' needs for products are changing from functional and performance aspects to customer-led type where customers can reflect on their needs on the products. The operation inside cars is executed by HMI. The push-return switch is utilized as the most intuitive mode of HMI; therefore, this push-return switch, which is widely used, has to be developed by assessing the preference and satisfaction of the customer. Method: The angle and curvatures, which are external factors that affect the feel of operation, are drawn through surveying the preceding research literatures. The stages to construct alternatives in experiments are as follows: (1) the tactile switch is replaced after dismantling the switch assembly to evaluate the internal characteristics proposed by preceding researches, (2) a drawing is prepared by using a design software, is printed using 3D printer, and then it is attached on the switch assembly, and (3) evaluation for satisfaction of operation is carried out by using a driving simulator. Results: Both the angle and curvature that are external factors of switch significantly affect the feel of operation. However, interaction between the two factors is found insignificant. Therefore, an optimum alternative is proposed considering the experimental outcomes. Conclusion: This study evaluates the satisfaction in operation that affects the feel of operation environment inside the cars. Based on the study results, a guideline for switch design in the center fascia is proposed. Application: This study is expected to be used as basic data for designing automotive switches, as well as switches in the industries similar with the operation environments of cars.

• Journal of the Ergonomics Society of Korea
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• v.29 no.1
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• pp.39-46
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• 2010

The growth of function in vehicle needs complex display and control system, the In-Vehicle Information System(IVIS). Although current IVISs are widely implemented in commercial vehicles, a new form of IVIS has been recently studied in order to reduce drivers' workloads. The purpose of this study is to suggest an appropriate menu structure of a new type IVIS, to be implemented on the instrument cluster panel, using Taguchi's parameter design. In the research, firstly, functions were selected that are appropriate to control through the instrument cluster among existing functions of current IVISs by quantitative evaluation of ergonomic principles. Then, menu structure alternatives were extracted by investigating priorities to those functions selected. Finally, menu structure alternatives were evaluated through an experiment and suggest the most appropriate one by applying Taguchi's parameter design. Taguchi method was used not only for planning an experiment but also evaluating alternatives. SN ratios were a key value to evaluate the alternatives and to find the most proper one. Through the research, the most appropriate menu structure for the instrument cluster IVIS was finally suggested among the alternatives and it is expected that the results of this research could provide a guideline to the instrument cluster IVIS.

• Journal of the Ergonomics Society of Korea
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• v.32 no.3
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• pp.267-271
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• 2013

Objective: The purpose of this study is to examine the test-retest reliability of paper-pencil test for investigating population stereotype of burner-control linkages of four-stove gas ranges. Background: Much of the research on gas-range stereotype strength has been performed using the paper-pencil test. While the use of the paper-pencil tests has the advantage of collecting data in a large group of subjects against reasonable costs, concerns regarding the reliability of the paper-pencil test has also been stated. Method: Three paper-pencil tests classified by intervals of test-retest were performed, in which eight types of burner-control arrangements were investigated. Sixty eight subjects were test-retested within two weeks, 85 subjects were test-retested within four weeks and 58 subjects were test-retested three times in series with interval of two and four weeks. Results: Chi-square test showed that three intervals of test-retest including two, four and two & four weeks have not statistically significant effect on subjects' responses irrespective of eight types of burner-control linkages dealt with in this study(p>0.10). Concordance rates of subjects' responses ranged between 73.5% and 100.0% for two-week test-retest, between 67.1% and 97.6% for four-week test-retest, and between 65.5% and 100.0% for two- and four-week serial test-retest. The concordance rates were linearly correlated with proportion of subjects' responses for stereotypes of burnercontrol linkages. Conclusion: It is concluded that the paper-pencil tests for investigating gas range relevant stereotypes could reproduce reliable results compared to baseline test within interval of four weeks. Application: The results of this study would be useful as an ergonomic guideline when designing the paper-pencil tests for stereotype relevant studies.