• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.101-111
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• 1998

CNS (Car Navigation System) is the most compatible candidate among various in-vehicle information systems as a provider of ITS (Intelligence Transport Systems) information. It generally consists of remote controller, display, CD-changer, GPS receiver and so on. Among them, display is the most important and critical element of the HMI (Human-Machine Interface) suggesting the digital map to the driver. Therefore, it is certain that the display gives cognitive, physical, mental and visual workloads to the driver which are directly related with the driver's and road safety with the success of ITS. Until now, various human factors techniques have been developed and applied to estimate the driver's workload and to collect the driver's requirements of the CNS digital map, for example, mental workload assessment, visual activity analysis, cognitive analysis and so on. In addition to these kinds of techniques, this research performed the human sensibility ergonomics approach to directly investigate and evaluate the driver's requirements and sensibilities of the real products.

• International conference on construction engineering and project management
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• 2015.10a
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• pp.179-182
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• 2015

Detecting and assessing human-related risks is critical to improve the on-site safety condition and reduce the loss in lives, time and budget for construction industry. Recent research in neural science and psychology suggest inattentional blindness that caused by overload in working memory is the major cause of unexpected human related accidents. Due to the limitation of human mental workload, laborers are vulnerable to unexpected hazards while focusing on complicated and dangerous construction tasks. Therefore, detecting the risk perception abilities of workers could help to identify vulnerable individuals and reduce unexpected injuries. However, there are no available measurement approaches or devices capable of monitoring construction workers' mental conditions. The research proposed in this paper aims to develop such a measurement framework to evaluate hazards through monitoring electroencephalogram of labors. The research team developed a wearable safety monitoring helmet, which can collect the brain waves of users for analysis. A bispectrum approach has been developed in this paper to enrich the data source and improve accuracy.

• Journal of the Ergonomics Society of Korea
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• v.35 no.2
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• pp.67-74
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• 2016

Objective: The aim of this study is to develop a farming shovel to reduce workload, which helps farmers lower the risk of musculoskeletal disease. Background: Most of work using farming tools including shovels requires repetitive works and awkward postures on body parts, and it could possibly cause work-related musculoskeletal disorders. It is necessary to develop and distribute farm equipment and tools in order to reduce physical workload. Method: To improve the most uncomfortable task perceived by ten farmers during the work with a shovel, the improved shovel was designed and made as a prototype for experiment for the comparison of the existing and improved shovels. Twenty males were recruited for this experiment, and muscle activity (%MVC) of six body parts and subjective discomfort ratings by body parts while working with a shovel were measured. A paired t-test was performed to compare physical workload between the existing shovel and the developed one. Results: A shovel applying foothold tied between shaft and blade was designed, which can help workers reduce repetitive bending of back and pressures for upper limbs while digging soil. According to compared evaluation of the developed shovel and the existing shovel, the developed shovel's %MVCs in all experimental muscles were significantly lower than those of the existing shovel. The developed shovel showed the biggest drop in perceived subjective discomfort rating of back, followed by arm and neck, compared to the existing shovel. Conclusion: It was confirmed that attaching a foothold to a shovel was an effective way of reducing workload in back and upper limbs during digging. Application: In the near future, if we put the prototype of developed shovel to practical use after making up for defects, it will help farm work environment be healthier and safer.

• Safety and Health at Work
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• v.9 no.1
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• pp.42-52
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• 2018

Background: Maintenance operations on-board ships are highly demanding. Maintenance operations are intensive activities requiring high man-machine interactions in challenging and evolving conditions. The evolving conditions are weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress. For example, extreme weather condition affects seafarers' performance, increasing the chances of error, and, consequently, can cause injuries or fatalities to personnel. An effective human error probability model is required to better manage maintenance on-board ships. The developed model would assist in developing and maintaining effective risk management protocols. Thus, the objective of this study is to develop a human error probability model considering various internal and external factors affecting seafarers' performance. Methods: The human error probability model is developed using probability theory applied to Bayesian network. The model is tested using the data received through the developed questionnaire survey of >200 experienced seafarers with >5 years of experience. The model developed in this study is used to find out the reliability of human performance on particular maintenance activities. Results: The developed methodology is tested on the maintenance of marine engine's cooling water pump for engine department and anchor windlass for deck department. In the considered case studies, human error probabilities are estimated in various scenarios and the results are compared between the scenarios and the different seafarer categories. The results of the case studies for both departments are also compared. Conclusion: The developed model is effective in assessing human error probabilities. These probabilities would get dynamically updated as and when new information is available on changes in either internal (i.e., training, experience, and fatigue) or external (i.e., environmental and operational conditions such as weather conditions, workplace temperature, ship motion, noise and vibration, and workload and stress) factors.

• Journal of the Korea Institute of Building Construction
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• v.15 no.1
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• pp.107-113
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• 2015

Recently mechanization construction methods are developed rapidly in the field of construction processing. The construction industry is one of the sector that still requires a lot of manual labor of the entire industry. There are still various kinds of work done by human labors, especially in the disassembling and separation of materials for recycling. However, database of relevant statistics including estimating standards are difficult to analyze by actual human workload, and furthermore the disassembling processes are being analyzed by qualitative assessment. This study attempted to introduce the accelerometer for the quantitative evaluation of human workload in the construction field. Still, it is possible to calculate the amount of energy which is required for the assembling and disassembling of nail and screw through three-dimensional accelerometer.

• Journal of the Ergonomics Society of Korea
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• v.29 no.3
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• pp.375-382
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• 2010

The purpose of this study was to analyze the risk factors of the musculoskeletal workload of mid-old-age food preparation workers by identifying the differences in the complaints of subjective symptoms between mid-old-age housewives and mid-old-age food preparation workers. This study was carried out on a total of 83 subjects from April 2009 through July 2009: 43 food preparation workers at the catering department of general hospital A, with a high rate of mid-old-age food preparation staff, and 40 full-time housewives (40~59 years old). The analysis of the relationship between the rates of the subjective symptoms of the two groups showed that the mid-old-age food preparation workers had a 7.8-fold higher risk of developing musculoskeletal diseases than the full-time housewives. The musculoskeletal workload of the mid-old-age food preparation workers included repetitive motions, uncomfortable postures, and heavy lifting. It is hoped that this study will help provide mid-old-age people with opportunities for appropriate economic activity and labor and will help improve their work postures and methods as well as their environmental-risk factors.

• Journal of the Korean Society of Safety
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• v.24 no.2
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• pp.69-75
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• 2009

It is well-known that lifting capacity of a worker is influenced by body posture during the task. When a task analyst make use of RULA and REBA Trunk and upper arm angles are recorded in a separate item. It means that the interaction between the angles of two body segments may be ignored in a final score. The NLE(NIOSH Lifting Equation) has been used to supplement this problem. However, there is no study to validate the result of RWL (Recommended Workload Limit) under the existence of interactions between trunk and upper arm angles. The goal of this study was to assess the effect of the interaction between trunk and upper arm angles. Three responses, including NMVC(normalized maximum voluntary contraction), RWL(Recommended Weight Limit) and subjective judgment in psychophysical method (Borg's scale), were recorded according to the combinations of three trunk angles and nine upper arm angles. The results showed that lifting capacity is highly influenced by interaction of two body segments(trunk and upper arm). It means that the task workload has to be analyzed along with the interaction of trunk angles and upper arm angles when the task analyst assesses potential risk factors on the postures. This study may be able to be a fundamental study to develop an assessment method for lifting task analyses according to body postures.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.4
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• pp.69-75
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• 2019

Since gasoline engines are based on a combination of a cast iron liner and an aluminum block, which have different thermal properties and stiffnesses, bore shape distortion is likely to occur during honing due to uneven thermal deformation. To solve this problem, many tests and evaluations are needed to support the development of a high-performance honing stone with low heat generation. Moreover, performance evaluation, which depends on inspection and observation after work, often requires much trial and error to optimize tool design, due to challenges in the accurate interpretation of results. This study confirmed that the assessment of grinding capability was clarified by evaluating performance under severe work conditions and by in-situ measurement and recording of current consumption (workload) and heat generation during operation. As a result of using a honing stone with excellent grinding performance in engine block manufacture-in which cylinder bore distortion caused by thermal deformation during manufacture is a problem-a noticeable improvement in the degree of cylindricity was observed.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.125-131
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• 2003

In recent years, the Korean Army made use of fork-lifters or conveyors when loading and/or unloading military material in order to prevent accidents and to promote efficiency of military material handling activities. However, in troops smaller thin battalions, manual material handling activities are still committed for many reasons. In this thesis, a brand new loading/unloading device for efficient military material handling or manual workers was developed, and its validation study was conducted through objective assessment based on electromyography, subjective assessment based on Body-Map technique developed by Corlett and Bishop, and finally work performance comparison. The results of EMG analysis showed that muscular workload improved by 24% when using the device compared to manual work without the device, and complain of each body part was remarkably reduced. In addition, remarkable effectiveness enhancement was observed in the work performance. Consequently, it could be concluded that ergonomic devices like one developed in this research should be studied further in the ergonomic sense as well as in the economical sense.

• Journal of Korean Academy of Nursing Administration
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• v.3 no.2
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• pp.123-136
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• 1997

The purpose of this study was to confirm the classification of nursing activity and to analyze the time of nursing workload in a new open hospital. The data were collected from 20 nurses working in 6 general nursing units by 4 trained observers. The tools used for this study were an observation recording sheet and a classification sheet of nursing activity. The classification sheet was constructed to be adaptable to each hospital system based on the instrument described in the literature. The results of the study are as follows : The direct nursing activities consisted of 6 sections, 33 subsections and the indirect nursing activities consisted of 14 sections, 53 subsections. The direct nursing activities included medication, measuring and observation, care of therapies, care of physical comfort, laboratory and treatment. The indirect nursing activities included preparation of medical utensils, collection of information and assessment, recording, phone communication, professional interaction related to patients, personal time, assigning work to staff, patient eaucation and training, interaction with lab, transfer of administration of utensils, checking physician's order, dietary service, management of pollution and contagion, guide direction. Nurses spent 127.6min for direct nursing activity during day duty. It was 24.5% of total nursing activity. Within that activity medication had the highest percentage of time(40.09%), followed by communication and education with patient(24.76%), measuring and observation (16.93%), laboratory and treatment (12.85%), care of therapies(3.21%) and care of physical comfort (2.16%). The time breakdown for indirect nursing activities is as follows ; the preparation of medical utensils 22.3%, collection of information and assessment 20.29%, recording 20.27%, phone communication 8.14%, professional interaction related to patients 7.33%, personal time 7.24%, with the remaining timeshared by staffing, patient education and training, interaction with lab, transfer of administration of utensils, checking physician's order, dietary service, management of pollution and contagion, guide direction. In the analysis of the relationships between the working time and the work allocation characters of the nurses(including nurse's experiences. nurse-patients ratio, nurse-rooms ratio, and character of nursing unit) ; There were no significant differences in direct-indirect nursing times between nurse's career years. There was significant difference in direct nursing time between assigned patient numbers. The nurses assigned larger number of patients spent significantly more time in direct nursing care than that of the smaller. On the other hand, there was no significant difference in indirect nursing workload between the assigned patient numbers. There were no significant differences in direct-indirect nursing time between an allocated patient's room numbers. There was significant difference in working time between working places. The nurse in the medical unit spent more time in direct nursing care than her counterpart in the surgical unit. However there was no difference in direct nursing time between two groups. The study results indicate that nurses spent less time in the direct nursing care than in the previous studies even though the hospital system has been modernized. On the other hand they spent much more time for the coordinating role within the interdisciplinary team and for the overlapping paperwork. Therefore it is recommended that patient oriented job description and more efficient usage of modernized utilities be made.