• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.125-137
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• 2009

Recently, the frequency in use of electric adjustable bed is going up by an increase in the elderly population. In bad ergonomic design for an electric adjustable bed causes some problems in the aspects of usability and safety. In particular, lots of accidents came from going up or going down an electric adjustable bed. In that case, the height of bed is very important factor for preventing an accident. This problem is related to its anthropometric factors. Therefore we carried out its anthropometric analysis and old people's standing action according the height of electric adjustable bed as an experimental study. As a result, we proposed some anthropometric design criteria and identified the effect of bed height when old people use it.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.961-962
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• 2009

• Journal of Drive and Control
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• v.18 no.4
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• pp.19-27
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• 2021

A bunker bed is a type of furniture that efficiently utilizes a narrow indoor space by having a high bed and using the empty space below as a living and storage space. The demand for multi-purpose furniture is increasing due to the recent increase in single-person households and wide-spread shared accommodation. According to the consumer research, one of the major drawbacks of a bunker bed was to get on and off the bed through a ladder or stairs. In order to overcome these problems, it was confirmed that the height adjustment function that can easily adjust the minimum and maximum heights of the bed was necessary. In this study, a height adjustable bunker bed was designed by using a gas spring that generates a repulsive force by the compressed gas inside. The design process consisted of the following three steps: Firstly, the hysteresis characteristics due to a friction and spring constant of a commercial gas spring were confirmed by measuring the repulsive force vs. compressed displacement. Secondly, requirements of the vertical lifting force exerted on the bed against gravity force were derived. Finally, the height-adjustable bed using the four-bar link mechanism was designed with 4 parameters so that the bed weight of 60-70 kgf could be adjusted to 800 mm in height by an affordable initial operation force. The performance was verified through prototype production and the results of vertical displacement and force to move were nearly the same as designed. In addition, an electrically operated height-adjustable bed was also designed with linear actuators and the performance was proved with the prototype.

• Journal of the Korea Safety Management & Science
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• v.18 no.1
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• pp.45-55
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• 2016

In this study we carry out usability evaluation for adjustable electric beds for home care that are used the most by the elderly, and examines dissatisfaction of users. In this sense, we performed an interview with stakeholders including bed users, developers and suppliers to develop usability evaluation contents. In addition, we carried out feasibility and reliability study over evaluation form through usability assessment, and developed usability evaluation indicator.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.2
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• pp.55-62
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• 2012

In this paper we propose a control system to preserve the interior angle between back section and upper leg section to be larger than 90 degrees using a single limit switch. To design the control system we analyze the kinematics of actuation mechanisms for the back section and the upper leg section, and find out an optimal solution for the controller design. Using a prototype control system we perform experiments to test the controller performance, and show that the interior angle between the back section and the upper leg section is always preserved larger than 90 degree. From the experimental results, we show the proposed control system is feasible to keep the body posture stability.

• Korean Journal of Human Ecology
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• v.16 no.6
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• pp.1243-1250
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• 2007

The purpose of this study was to compare government guidelines and foreign guidelines related to furniture design for elderly. Future elderly will increasingly accustomed to the provisions of improved housing, education and welfare in comparison with our forebears. Also, there will be upgrading and different need for elderly furniture in our market. The results were as follows. The height of bed was based on the height of wheelchair seat, commonly. A adjustable bed was recommended for abled and disabled elderly. A pull-down shelf, drawer, empty space under chest, folding or sliding door in wardrobe and so on were recommended as a elderly furniture. It were good adjustable sink on human scale. There were need the empty space under sink for wheelchair users, one-touch or lever faucet, etc. There have given a little furniture design guidelines for elderly in Korea until now. But those guidelines haven't been considered enough human scale of elderly including wheelchair user. Because the close investigations have not made about abled and disabled elderly for their furniture design. So first of all, the government should be examined elderly physical size more accurately for elderly furniture design. The guideline for elderly furniture design should be for abled elderly and the disabled, too.

• Journal of the Korea Furniture Society
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• v.25 no.4
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• pp.304-318
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• 2014

Bed for elderly and disabled, including the United States developed the industry Americas, and European countries, mainly in the production of products has dominated the world market. In large hospitals, and dependent products are sold at high prices. On the other hand, improvement of living standards of our country and to the advancement of residential culture of the demand for luxury products is increasing. The study of elderly Edition mattresses have been developed mainly in Europe to maximize the use of sleep can increase the efficiency of products has been studied. Due to the increase in elderly population Elderly Hospital, which is installed in the elderly silver town Edition requires the dissemination of the mattress in the bedroom several times a day resting and sleeping, eating, etc. Designing a variety of actions are needed. Edition of the elderly in Korea developed the design of bed with bed design and the manufacturer and the Institute for Ergonomics, welfare agencies and to build organic cooperation system under the direction of a professional designer to develop and you need to configure the space and the results of such actions by the distribution of cheap materials, ergonomic mattress for optimal development of behavior analysis to the need to promote the convenience of the user.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.5
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• pp.424-431
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• 2007

This thesis proposed H-Bridge Multi-Level Inverter for Fluidized Bed Combustion Boiler Secondary Air Fan in 200MW thermal power plant. The adjustable speed drive systems improve the efficiency in lightly load condition and extend the life span of motor by limiting the over current at starting. H-Bridge Multi-level Inverter is composed of the several series low voltage power cell inverters, which have the independent isolated do link, in each phase. KEPRI(Korea Electric Power Research Institute) has successfully completed to develop, install, and commission H-Bridge Multi-level Inverter(6.6kV, 1MVA). This thesis gives a full detail about H-Bridge Multi-level Inverter, proposed boiler DCS(Distributed Control System) logic, and commissioning test result.

• Proceeding of Spring/Autumn Annual Conference of KHA
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• 1990.09a
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• pp.15-24
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• 1990

The purpose of this research is to provide the informations on built - in closets and storage in urban apartment houses in korea, considering the mode in living. Since the number of household goods and furniture might be related with the unit size of house(L D K) and district (Seoul. Pusan, Incheon) all data also were evaluated by the struclure of dwelling space and urban area in korea. For being importance of "Anbang" for indoor living, in which Znagnnng, Mungap, a dressing table and hanger are prepared. Preparation of new space in various ways. so many living tools are being used, for example the dinner table with adjustable supporters. A room is specially prepared for storage of season's living goods and furniture. It is very interest that the bed is still net popular, because that is considered as obstruction for the function of "Anbang", specially in small size apartment. Built - in closets and storage In "Anbang" is greatly needed, because most of activities of living involving sleeping are done In that space.

• Science of Emotion and Sensibility
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• v.2 no.1
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• pp.95-103
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• 1999

침대에서의 체압분포는 수면 안락감에 중요한 영향을 미치는 요인중의 하나로 고려되어져 왔다. 체압분포는 사람의 몸무게에 의하여 침대와 누운사람 사이의 접촉면에서 발생하는 압력의 분포를 말한다. 안락한 체압분포 패턴을 결정하기 위하여 사용자가 침대 8부분의 높이를 조절할 수 있는 가변침대를 사용하였다. 체압분포 측정은 각 수면자세(바로 누운 자세, 옆으로 누운 자세, 엎드린 자세)에서 가변침대의 초기상태와 피실험자가 편안한 체압분포 패턴을 유지하도록 높이를 조절한 상태에서 이루어졌다. 본 연구에서는 각 수면자세에서 체압비와 선호하는 체압비의 특징을 알아보았다. 본 연구의 결과를 요약하면 다음과 같다. - 각 수면자세에서 엉덩이 부분의 체압비가 가장 높았으며, 바로 누운 자세는 40% 이상의 체압비가 엉덩이에 집중한다. - 각 수면자세에서 전체적으로 머리와 다리의 높이가 다른 부분보다 높은 것을 선호하는 경향을 나타난다. - 바로 누운 자세에서는 유추를 기준으로 신체가 W형이 되도록 머리, 요추, 대퇴부분의 높이를 올리는 것을 선호한다. - 엎드린 자세는 머리와 다리부분의 높이를 증가시킴으로써 신체이 곡선이 U형이 되도록 하는 것을 선호한다.