• Journal of the Ergonomics Society of Korea
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• v.36 no.2
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• pp.69-86
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• 2017

Objective: The present study is intended to develop an improved bus seat armrest design by evaluating various bus armrest designs from ergonomic aspects. Background: An ergonomic armrest design which considers the sitting postures and body shapes of passengers can improve the convenience and comfort of a bus seat. Method: Subjective satisfaction of each of five design dimensions (length, width, height from seatpan, shape, and angle) was evaluated for seven bus seat armrest designs in various sizes and shapes by 58 participants (28 males and 33 females) using a 7-point scale (1: very dissatisfied, 4: neutral, and 7: very satisfied). Improved bus seat armrest designs adjustable in length and rotatable to the left or right (sliding and rotating armrest, SRA) with a concave, flat, or convex shape of the upper part were developed by considering the preferred design features and the body size and shape in sitting posture and needs of passengers and then compared with a conventional armrest. Results: A bus seat armrest with a wide width (40~50mm), a long length (360mm), a lower height (213mm), and a curved shape was found significantly preferred in terms of comfort. The proposed armrest designs (SRA-convex, SRA-flat, and SRA-concave) improved satisfaction by 46~62% for length suitability, 184~216% for width suitability, 205~214% for angle suitability, 138~181% for contact area suitability, and 49~64% for height suitability, 138~174% for comfort, and 93~111% for overall satisfaction. Conclusion: The preferred design features and passengers' needs of bus seat armrest were identified and the SRA designs were recommended for better usability. Application: The ergonomic design process of bus seat armrest employed in the present study can be applied to designing armrests in various vehicles for better convenience and comfort.

• Journal of the Ergonomics Society of Korea
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• v.25 no.2
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• pp.1-10
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• 2006

In spite of the rapid increase of computer use in our everyday life, not much effort is undertaken to take measures to prevent Musculoskeletal Disorders(MSDs). In this paper, we suggest a movable armrest which would lower the exposure to the MSDs, especially on the vicinity of arm. The aim of this study is to determine whether there are differences in wrist angle variations, forearm muscular loads, comfort and normal performance between the invented movable armrest and a conventional armrest when using a computer mouse. Eight experienced VDU workers performed a standardized simple task set which consists of 15 detailed tasks with each armrest. The wrist angle variations in the right arm were registered by electrogoniometer and the muscle activities in the shoulder, deltoid and two extensors in the forearm were also registered by electromyograph. The subjects rated perceived comfort while performing the tasks with each armrest. Working with the invented armrest, compared to general, gave significantly decreased wrist angle variations at most of the detailed tasks of both biaxial movements. Moreover, as the distance of targets increased, the difference of muscle activities in two different situations trend to be increasing. At the same time, in work with invented armrest, the subjects rated more comfort and they showed decreased normal performances in 8 detailed tasks which were mainly caused by macro moving time.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.5
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• pp.797-804
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• 2012

Magnesium has a long tradition of use as a lightweight material in the field of automotive industry. This paper presents the design optimization process of Mg armrest frame to minimize its weight by replacing the steel frame. formerly, the analysis of steel armrest frame was peformed to determine the design specifications for Mg armrest frame. The initial design of Mg armrest frame was carried out by topological optimization technique. After six types of design variables and four types of response variables were defined, DOE(Design of Experiment) and RSM (Response Surface Method) were applied in order to measure sensitivity of design variables and realize optimization through regression model. After design optimization, the weight of the optimized Mg armrest frame was reduced by about 3% compared to the initial design of the Mg frame and was decreased by 41.7% in comparison with that of the steel frame. Some prototypical armrest frames were also made by die casting process and tested. The results were satisfying for its design specifications.

• Analytical Science and Technology
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• v.24 no.4
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• pp.290-297
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• 2011

In present, evaluation method for car cabin air quality has been developed in ISO, China, Japan. Also The management standard for new produced car has been applied since 1, July, 2010. To manage car cabin air quality, It is important to evaluate VOC emitted from interior material. In this study, complete component of door trim armrest was evaluated in accordance with ISO 12219-5, cut component was evaluated in accordance with ISO 12219-3. The vapour gas was collected with stainless tube packed with Tenax TA and analyzed with TD-GC/MS. It was confirmed that emission rate of each compounds was difficult in each evaluation method. As a result, to evaluating each components composing door trim armrest, main sources of emitting VOCs in door trim armrest were PP substrate and adhesive.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.882-886
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• 2004

A nation have the regulation for a vehicle safety and interested in the side impact of a vehicle. But we spend a lot of money and time for the side impact test. So we must design a vehicle parts regard to the side impact test. This paper describes a new test method for side impact test. We used DFSS(Design For Six Sigma) process for design of door trim armrest. We searched the door trim armrest control factor and made the experiment plan. We researched the optimal design factor and improved the abdomen injury value of the human dummy.

• Journal of the Ergonomics Society of Korea
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• v.33 no.2
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• pp.97-108
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• 2014

Objective:The present study is intended to evaluate the usability of a console chair for a weapon locating radar by comparing with different kinds of chair design. Background: Console chairs need to be ergonomically designed to reduce physical workload of operators and improve mission capability; few studies have been reported which systematically evaluate usability of military console chairs. Method: Ergonomic design of a console chair, a bus seat, and an office chair was evaluated in terms of headrest, seatback, seatpan, armrest, and controller on a 7-point scale. Ten males in their 20s and 30s were recruited considering the demographic characteristics of console operators. Results: The satisfaction scores of the console chair for headrest, seatback, and seatpan were significantly higher than those of the bus seat (mean difference [MD] = 0.9) and office chair (MD = 1.3). Meanwhile, the satisfaction scores of the console chair for armrest and controller were significantly lower than those of the office chair (MD = -1.4) and bus seat (MD = -2.2). Conclusion: The armrest and controller of the console chair needs ergonomic improvements for better comfort. Application: The evaluation results of the console chair would be of use for ergonomic console chair design.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.130-138
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• 2004

In this paper, the structural strength of a rolling stock seat were numerically evaluated under several design load conditions based on the UIC requirements. The rot]ins stock seat was designed for the high speed train of a Chinese conventional line. To maximize its weight reduction and structural strength, an aluminium alloy, ALDC8-T5, was applied to the base frame, side frames and armrests. The designed seat frame satisfied the strength requirements on inertia loads and fatigue test conditions. However, it couldn't satisfy the requirements on the static test conditions of UIC 566 OR. Therefore, some design modifications were suggested and numerically evaluated whether the static test requirements could be satisfied or not.

• Journal of the Korean Society for Precision Engineering
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• v.28 no.2
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• pp.211-218
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• 2011

We reported the design, prototype, test drive, and mechanical & electrical engineering analyses of a power-lifting wheelchair using mecanum wheels. Mecanum wheels enable translational and rotational movement of the device in any direction on the ground. The power-lifting capability enables the seated individual to reach the standing height of a non-disabled individual. This mecanum wheelchair is fully controlled by the joystick attached to the armrest. The motion of the wheelchair and lifting action of the seat were studied using statics and dynamics. We believe this mecanum wheelchair is a prime candidate for commercial production.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.49-58
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• 2003

In this paper, the structural strengths of a rolling stock seat were numerically evaluated under several design load conditions based on the UIC requirements. The rolling stock seat was designed for the high speed train of a Chinese conventional line. To maximize its weight reduction and structural strength, some aluminium alloys like 6N01-T5 and ALDC8-T5 were applied to the base frame, side frame and armrest. The designed seat frame satisfied the strength requirements on inertia loads due to accelerations, and fatigue test conditions. However, it violated the requirements on the static test of UIC 566 OR. Some design modifications were suggested and numerically evaluated to satisfy the static test requirements.

• Proceedings of the ESK Conference
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• 1994.04a
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• pp.86-101
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• 1994

The primary objectives of this research are to survey actual condition and propose the improved standard size for office chairs. In order to accomplish this objectives, questionnaire method was used. The subjects for investigation are 271 office sedentary workers from 19 office workplaces. The survey of a actual condition showed that the office chairs included many contr- oversial points which cause occupational health problems. The main causes of office sedentary worker's health problems are insufficient adjustabilities and inappropriate design specifications. Expecially, insufficient adjustabilities led harmful sitting postures. To improve the existing Korean standard size for office chairs, anthropometric procedure was developed. In this approach, six design factors were determined, that is, seat pan height, seat pan width, seat pan depth, seat pan inclination, armrest height and width. The study found that improved Korean staneard size was strikingly different from existing standard.