• Journal of Auto-vehicle Safety Association
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• v.11 no.4
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• pp.57-62
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• 2019

The seat back frame of the vehicle is subjected to load on the passenger behavior. Because of steel material, it is necessary to optimize the frame considering lightweight and safety. In this paper, finite element analysis is used for the optimal design of the seat back frame. First, a lightweight material is applied to reduce the weight of the seat back frame. Secondly, the design position of the pipe part fastened in the seat back frame was selected by considering the strength against the load generated by the occupant. Third, the shape of the side frame was derived by performing the phase optimization analysis for the AFT load condition. And we have compared the initial model with the optimal model to verify the light weighting and safety. As a result, the optimal design model of the seat back frame satisfying the weight reduction and safety has been proposed.

• Journal of the Ergonomics Society of Korea
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• v.28 no.2
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• pp.35-55
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• 2009

The purpose of this study was to analyze the somatotypes of women in the early 20's, which were likely to deform due to bad posture in growth period. Accordingly, bodies of women aged 20 to 24, whose growth stopped, were measured directly and indirectly, and factors related to body shapes were extracted, body shapes were categorized based on the data, and the characteristics of each body shape were analyzed. As a result, 10 factors related to body shapes were extracted in the factor analysis, and body shapes were categorized into 6 types. Type 1 was the volume of body that was big and the longest; and the general frame was large. The straight body shape with small back protrusion; the shoulder is relatively thick and the width of the shoulder was normal. Type 2 was the volume of body that was the biggest and the upper body was the longest; the general frame was of average height. The forward body shape with the back flat; the shoulder was very thick, wide, and serious leaning forward. Type 3 was a body that was thin and the shortest. The sway-back body shape with big curvature at the back; the shoulder was thin, narrow, and straight. Type 4 was a body that was short stature, and the general frame was of average build. The forward body shape with the most serious back protrusion; the shoulder was normally thick, narrow, and straight. Type 5 was a group with small body, and the lower body and general frame are long. The sway-back body shape with protrusion at the upper shoulder and the sides leaning backward; the shoulder was thin, wide, and leaning forward. Type 6 was a thin and short body; and the general frame was small. The lean-back body shape with the smallest back protrusion and leaning backward; the shoulder was thin, narrow, and leaning backward. Characteristics of the classified body shapes can be used in producing ready-made clothes, and it is hoped that there will be follow-up studies on clothing pattern design and production based on this result.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.3
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• pp.91-100
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• 2004

This study presents the development of a new aluminum seat frame for the commercial bus. Back moment and seat belt anchorage analysis of the conventional steel seat frame was conducted as a base model. Effective aluminum section dimensions for aluminum pipe were calculated from equivalent stiffness and equivalent weight study. Back moment and seat belt anchorage strength with the developed aluminum seat frame were compared to those of the base model. Additionally, to pass the fatigue test, shape modification of side frame assembly was conducted. From this study we could reduce the weight of seat frame more than 5 kg. And the current analysis model and procedure can provide useful informations in designing a new commercial car seat and can reduce the overall design cost and time.

• Journal of the korean Society of Automotive Engineers
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• v.16 no.1
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• pp.10-21
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• 1994

본 연구에서는 현재 자동차의 좌, 우측 Back Mirror의 부품중의 하나인 Frame을 현재 Zinc Diecasting 제품을 플라스틱으로 대체하는데 따른 여러가지 문제점을 플라스틱으로 대체하는데 따른 여러가지 문제점을 플라스틱 사출성형 CAE 해석을 이용하여 검증한 뒤 그 결과를 토대로 실제 제품개발 및 금형개발 등에 응용하기 위하여 연구를 행하는데 그 목적이 있다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.11
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• pp.4956-4962
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• 2012

Among the various parts of automobile, automotive seat is the most fundamental item that ride comfort can be evaluated as the direct contact part with human body. Automotive seat must have the sufficient rigidity and strength at the same time with ride comfort. In this study, cushion frame and back frame at car seat are modelled with 3D. There are structural simulation analyses about 3 kinds of tests on torsion strength, vertical load strength and back frame strength. In the analysis result, the initial total deformation and the permanent total deformation has the maximum values of 5.4821 mm and 0.02539mm respectively at the torsion strength test of cushion frame. Total deformations at front and rear end parts of cushion frame become the values of 2.1159mm and 0.0606mm respectively at the test of vertical load strength of cushion frame. In case of more than this load, the maximum value of total deformation also becomes 3.1739mm. The maximum value of total deformation becomes 0.18634mm at 3 kinds of the strength tests on back frame. By the study result of no excessive deformation and no fracture cushion frame and back frame at automotive seat, the sufficient rigidity and strength to guarantee the safety of passenger can be verified.

• Journal of the Korean Society of Safety
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• v.15 no.1
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• pp.80-85
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• 2000

The hydroforming process is rapidly gaining popularity in the sheet metal forming industry. In this study, hydroforming process is applied to the seat back frame. The load-deformation characteristics of seat frame are simulated according to the test requirements by FMVSS. Structural analyses were performed with an analysis package program named I-DEAS for the conventional and the hydroforming seat back frame. The seat back frame made by hydroforming is not only about 23 percent lightweight, but also about 20 percent high strength compared with conventional that.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.10
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• pp.16-23
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• 2020

Vehicle seats provide a comfortable ride for passengers by properly absorbing vibrations and shocks transmitted during driving. Vibration analyses on three models with different shapes were carried with the same material properties and constraint conditions. By varying the height of the seat-back, models 1, 2, and 3 were designed according to the inclined angle of the seat-back frame. Models 1, 2, and 3 were modeled with relatively simple designs using CATIA. The areas touching the buttocks of passengers show the most deformation. This work shows that seat durability and stability can vary depending on the shape of the seat design.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.1
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• pp.26-35
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• 1995

Bo-Back-N ARQ is widely used in packet networks for error and flow control methanisms. This paper analyzes the network throughput under the go-back-N schem. Contrast to other analytic methods which assume independent frame losses or the first order Markov frame analytic methods which assume independent frame losses or the first order Markov frame losses concoptually, the proposed method takes into account the correlation between successive frame losses in a congested node. Computer simulation shows that our method generates more accurate performance results that independent assumption method. We apply the proposed method to analyze the performance of BWM in high speed networs. Our results show that BWM maintains the independence between traffic streams.

• Journal of Information Processing Systems
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• v.8 no.4
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• pp.739-748
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• 2012

We propose an analytic model to compute the station's saturated throughput and packet delay performance of the IEEE 802.11 DCF (Distributed Coordination Function) in which frame transmission error rates in the channel are different from each other. Our analytic model shows that a station experiencing worse frame error rates than the others suffers severe performance degradation below its deserved throughput and delay performance. 802.11 DCF adopts an exponential back-off scheme. When some stations suffer from high frame error rates, their back-off stages should be increased so that others get the benefit from the smaller collision probabilities. This impact is then recursively applied to degrade the performance of the victim stations. In particular, we show that the performance is considerably degraded even if the frame error rate of the victim station satisfies the receiver input level sensitivity that has been specified in the IEEE 802.11 standard. We also verify the analytic results by the OPNET simulations.

• Journal of Power Electronics
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• v.18 no.5
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• pp.1424-1433
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• 2018

This paper presents a novel space vector pulse-width modulation (SVPWM) to synthesize an arbitrary non-sinusoidal phase voltage. The key of the proposed method is that the switching vectors used to comprise the reference vectors in the ${\alpha}_1-{\beta}_1$ frame and the ${\alpha}_3-{\beta}_3$ frame are decoupled. In the ${\alpha}_1-{\beta}_1$ frame, the reference vector is comprised by near two large vectors. The corresponding vector comprised by the two vectors in the ${\alpha}_3-{\beta}_3$ frame is considered as a disturbance, which is restrained by close-loop control. In the ${\alpha}_3-{\beta}_3$ frame, there are two methods to comprise the reference vector. Method I is a near two middle vectors method. Method II uses near four vectors (two middle and two little vectors). The proposed SVPWM using decoupled switching vectors can guarantee a maximum modulation index in the ${\alpha}_1-{\beta}_1$ frame. The effectiveness of the proposed method is verified by simulated and experimental results under various operation conditions.