• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11a
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• pp.444-449
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• 2001

The purpose of the work is to improve comfort of a car seat, especially dynamic comfort which affects driver's discomfort during the long time driving. Definition of dynamic comfort was made before the investigation of which parameter affects seat comfort. In order to optimize design parameters so as to maximize seat comfort as well as to know the cause of discomfort, benchmarking on a target vehicle and competitive vehicles was performed, which showed both the vibration transmission characteristics and the compression set due to dynamic loading should be reduced. As a solution ball rebounds was increased by about 10％ of the original foam, which showed reduction of S.E.A.T. value by 10％ and of compression set by 60％.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.3
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• pp.14-21
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• 2020

The automotive seat appropriately absorbs the vibrations or shocks transmitted through a vehicle when it is in operation so as to provide a comfortable ride for passengers. In this study, the structural strength and durability of each model were investigated using structural analysis. The natural and critical frequencies at the seat were analyzed through vibration analysis. Through the results of this study on automotive seat frame models, the durability against the load and vibration is shown to be dependent on the configuration of the model.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.16 no.6
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• pp.47-54
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• 2017

This study analyzed air suspension seat frame structure and vibration for 50 - 180 kg mass driver to obtain optimum seat design parameter values for the equivalent spring constant and damping coefficient. Various air suspension seat frames were designed following WTS-003 and KS B 6839 standards, and then evaluated using finite elements analysis. Resonance and vibration tests were performed according to the 78/764/EEC standard.

• Journal of Ocean Engineering and Technology
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• v.28 no.2
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• pp.160-166
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• 2014

Because of industrial development, industrial facilities are becoming more complex and diversified. Plant industries are focused on productivity improvement, cost reduction, and product uniformity by simplifying production processes using automated control. Furthermore, plant industries require higher pressures and temperatures to improve energy efficiency. For this reason, the valves used in plants are operated under harsh conditions. Globe valves and gate valves are mainly used for high pressure these days. However, these valves have various problems, including low maintainability and high cost, due to structural problems. Therefore, butterfly and ball valve applications are increasing in industrial plants. This paper suggests a quadruple-offset butterfly valve that is applicable to bi-direction use, and the principle design parameters are suggested. The selected design parameters are an eccentric flange center line and shaft centerline(Offset 1), an eccentric seat centerline and disc shaft centerline(Offset 2), the angle between the flange centerline and seat wedge angle(Offset 3), the angle between the vertical direction of the disc shaft centerline and seat centerline(Offset 4), and the seat engagement angle. To analyze the interaction effect of the design parameters, ANOM and ANOVA were performed with an orthogonal array. The parameters were found to have effects in the following order: Offset 2, Offset 1, engagement angle, Offset 3, and Offset 4. The interaction between the parameters was insignificant.

• Science of Emotion and Sensibility
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• v.13 no.2
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• pp.381-390
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• 2010

The automotive seat comfort evaluation was to begin a key aspect in seat design. It depended largely on the basic mechanical aspect such as geometric parameters of seat, choice of suspension system and cushion material used. Until recently, seat comfort evaluation advanced to evaluate subjective sensitivity of human. The external literatures showed in the last decade, there have been very few attempts to establish and document automotive seat comfort evaluation. In 2006 Smith, D. proposed the statistically reliable tool in giving a numeric rating for set comfort and the tool was used in the many country. On the other hands, we, in Korea, had not the reliable tool for the automotive seat comfort evaluation. So that, we studied to develope the questionnaire for seat comfort evaluation based on Smith, D.(2006) and some studies. As a result, we developed 36 contents for the automotive seat comfort evaluation with the help of professional in Korean automotive industry. Here, 36 contents were identified as the dimensions that represent the human sensitivity and psychological feeling on comfortable seat. Also, we derived the priorities for the 36 contents by using analytic hierarchy process (AHP), based on the judgments of 30 experts and drivers. This study will help the designers and developers clarify the conceptual and abstract aspect of the design evaluation by proposing a more systematic and process-oriented method.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.11a
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• pp.675-679
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• 2006

Today, the interior noise perceived by the occupants is an important factor in the design of automotive interior assemblies. Buzz, Squeak and Rattle Noises in a Seats are one of the major concerns mentioned above. In this study, the terms 'Buzz, squeak and rattle' were defined as the noise originating from structural vibrations in an assembly. And, the BSR noise of vehicle seat was investigated and the improvement of BSR noise level was confirmed though the structural treatment based on the structural analysis results from the modal and sound intensity of seat.

• Proceeding of EDISON Challenge
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• 2016.03a
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• pp.256-261
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• 2016

In this paper, Shape optimal design for a chair with 4 legs and 2 stretchers consisting of stainless steel was conducted. The shape was transformed by identifying stress and deformation for the part of leg and stretcher. In addition, load condition and mesh was designed using Hypermesh. The stress analysis was carried out using CSD_Elast that is one of EDISON program. In seat test, Maximum equivalent stress was showed at the contact part between seat and legs. As a result, a leg cross-section with rectangular and arch was designed. And optimal height of stretcher was found to reduce a deformation. Also, maximum deformation was reduced by designing a stretcher with ellipse cross-section. So, Optimal chair having 4 legs with rectangular cross section and 2 stretchers with ellipse cross section was shown to satisfy the safety ratio.

• Journal of the Korean Society for Precision Engineering
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• v.26 no.3
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• pp.88-97
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• 2009

The vacuum die casting techniques can diminish the porosity of products and provide better surface appearance by the ordinary high pressure die casting process. The vacuum system can also reduce the cold laps in the die casting process and minimize the overflow pockets of the die. The vacuum system does not need high pressures to die cast compared to the ordinary die casting process, and so enables die casting of large parts for a given machine size. Parts made by the vacuum system have higher strength and more elongation than parts made by the ordinary die casting systems. In this paper, we designed and produced the Magnesium seat frames using the vacuum die casting processes. The new Magnesium seat frame was designed to satisfy safety regulations. Some safety test procedures of the seat frame were simulated by the finite element method. We obtained 10% weight reduction by design modification of seat frames compared to the current model. Flow simulations were carried out to minimize the trial and error in producing the parts. The die casted parts using vacuum systems resulted in better mechanical characteristics and no defects compared to those without vacuum systems.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.40-46
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• 2013

This paper describes the suggestion of the special seat with the auxiliary plastic member for movie theater chair. In the previous paper, we have reported on the development of foaming sponge seat with the auxiliary spring member. And we have confirmed that it was more effective on vibration transfer than the chair seat of foaming sponge only. In this study, we have examined the major design parameters needed in the development of a foaming sponge seat in which the mesh type plastic member are inserted to improve the vibration transfer effect of a chair seat. By applying experimentation to the prototype as well as the experimental modal analysis method, we made sure that the effect of the vibration transfer could be improved through the use of a mesh type plastic member as similar as the auxiliary spring member.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.6_3
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• pp.1173-1182
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• 2022

According to the National Fire Agency, there were 61 traffic accidents of Fire engines in 2021. That is an increase of about 80% compared to the previous year. And the number of injuries and deaths increased by more than 300%. According to the survey of this study, less than 25% of firefighters wore seat belts of Fire engines during dispatch, contrary to the rapid increase in injuries and deaths. About the reasons for why firefighters do not wear seat belts, It can be found in aspects that are related to personal consciousness, organizational culture, and firefighting dispatch. The number of dispatches will increase in the future, this is considered to be a serious problem for the stability of the firefighting organization. In this study, a seat belt should be designed newly and proposed to improve the seat belt wearing policy.