• 대한인간공학회지
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• 제33권2호
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• pp.125-134
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• 2014

Objective: The purpose of this study is to evaluate integral seat desk used in universities through comparison of real dimension values of the desk with KS/ISO standard and questionnaire survey. Background: School furniture that helps students sit comfortably for longer periods of time and allows for better concentration on learning is important. However, seat and desk have been generally designed based on the industry practice rather than user's anthropometry, and seats and desks used in universities of Korea have not been ergonomically evaluated. Method: Real 13 dimensions of the desk used in K University were measured using tape measure and inclinometer, and the dimension values were compared to the KS standard of desk and chair for lecture room (KS G 4210) and ergonomic design principles found in relevant references. Subjective appropriacies and preference for the desk were investigated based on questionnaire survey, in which 121 (male: 91, female: 30) college students participated. Results: Several dimensions for the desk and chair investigated except desk depth and width, leg room width, seat width have not met the KS standard, but all dimensions satisfied ergonomic design principles available in references. The questionnaire survey revealed that appropriacies for desk surface size, seat pan depth, seat pan cushion and backrest curvature were under middle point of 3.0, and that those for the other dimensions showed higher scores exceeding 3.0. Conclusion: The integral seat desk widely used in universities showed some design problems in terms of standards of KS G 2010 and KS G 4210, and ergonomic design principles. Compared to the general desk with separated desk and seat, subjective preference on the integral seat desk was low. Application: This would be used as a valuable guideline when designing or choosing new integral seat desk with high satisfaction of students.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1994년도 춘계학술대회논문집
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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.

• Membrane and Water Treatment
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• 제5권2호
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• pp.123-146
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• 2014

Safe water has becoming a competitive resource in many parts of the world due to increasing population, prolonged droughts, climate change etc. The development of economical and stable materials and methods for providing the fresh water in adequate amounts is the need of the water industry. Nanomaterials have unique characteristics e.g., large surface areas, size, shape, and dimensions etc. that make them particularly attractive for removing various contaminants from polluted waters. Nanotechnology based multifunctional and highly efficient membrane processes are providing affordable solutions in the new era that do not rely on large infrastructures or centralizes systems. The objective of the current study is to review the possible applications of the membrane based nanomaterials/composites for the removal of various contaminations from polluted waters. The article will briefly overview the availability and practice of different nanomaterials based membranes for removal of bacteria and viruses, organic compounds and inorganic solutes etc. present in surface water, ground water, seawater and/or industrial water. Finally, recommendations are made based on the current practices of nanofiltration membranes in water industry for a stand-alone membrane filtration system in removing various types of contaminants from polluted waters.

• Coupled systems mechanics
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• 제7권2호
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• pp.233-254
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• 2018

In order to reduce the dependency on fossil fuels, a policy to increase the production capacity of wind turbine is set up. This can be achieved with increasing the dimensions of offshore wind turbine blades. However, this increase in size implies serious problems of stability and durability. Considering the cost of large turbines and financial consequences of their premature failure, it is imperative to carry out numerical simulations over long periods. Here, an energy-conserving time-stepping scheme is proposed in order to ensure the satisfying computation of long-term response. The proposed scheme is implemented for three-dimensional solid based on Biot strain measures, which is used for modeling flexible blades. The simulations are performed at full spatial scale. For reliable design process, the wind loads should be represented as realistically as possible, including the fluid-structure interaction (FSI) dynamic effects on wind turbine blades. However, full-scale 3D FSI simulations for long-term wind loading remain of prohibitive computation cost. Thus, the model to quantify the wind loads proposed here is a simple, but not too simple to be representative for preliminary design studies.

• 대한인간공학회지
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• 제9권2호
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• pp.55-63
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• 1990

School children sit long on chairs in their classrom. Their posture is closely related to their chairs. Study of this relationship is very imporant for the health and education of school children. This report presents the results of study condcuted to determine the present status of classroom chairs and solve any problems identifede. The study involved 125 teachers in Seoul and Pusan, 175 fourth graders in Seoul, and 109 fourth graders in Puasn. The body dimensions of the school children and the dimensions of their chairs and desks were measured, and their postures while they studied at their desk were photographed. The following problems were identified as a result of the investigation: (1) Chairs are allocated to pupils according to their stature. (2) The teachers are not satisfied with the chairs and the method by which the chairs are allocated to their pupils. (3) The pupils complain of low seat height, narrow seat, and hard backrest, among other conditions. (4) The pupils select a chair one size larger than that suggested by their body size. (5) The poor posture of the pupils is traced to the seat height and sasyaku$(sitting height {\times} 1/3-1)$ of their chairs, their habit, their way of holding pencils, and lack of instruction by their teachers. The following recommendations are made to solve these problems: (1) Adjust the seat height and desk height to accommodate the pupils. (2) Provide both teachers and pupils with adequate knowledge of chails. (3) Provided each pupil with one desk and make the desk adjustable to sit his or her body dimensions. (4) Allocate a chair and desk to each pupil for his or her exclusive use. (5) Reserch and develop conversion tables that help to find suitable chails for individual pupils. New values of sasyaku and desk height, not specified in Korean Industrial Standards(KS), are proposed.

• 한국CDE학회논문집
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• 제9권4호
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• pp.277-285
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• 2004

In this paper, a 2 DOF haptic yawing joystick for use as the navigation input device in virtual environments is introduced. The haptic yawing joystick has 360° range for yawing motion and ±100° for pitching motion. The device can support weights of up to 26N for χ axis and 10N for axis with 10kHz of sampling rate. The size of the haptic yawing joystick is so small that it can be assembled on armrest of an arm chair and has relatively larger work space than other conventional 2 DOF joysticks. For the haptic yawing joystick, an ellipse navigation algorithm using the user's velocity in the virtual navigation is proposed. The ellipse represents the velocity of the user. According to the velocity of the navigator, the ellipse size is supposed to be changed. Since the path width of navigation environments is limited, the ellipse size is also limited. The ellipse navigation algorithm is tested in 2 dimensional virtual environments. The test results show that the average velocity of the navigation with the algorithm is faster than the average navigation velocity without the algorithm.

• 디자인학연구
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• 제16권3호
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• pp.319-328
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• 2003

본 연구는 보다 나은 소규모 음식점의 환경개선을 위한 기초적 조사로 서울시에 있는 6개 대학 주변에서 현재 운영되고있는 20평($66m^2$) 이하의 분식 또는 간단한 일식 및 한식류를 판매하는 음식점 48곳을 대상으로 좌석배치의 치수를 파악하였으며, 그 결론 및 제언은 다음과 같다. 첫째, 소규모 음식점에서 1인당 좌석 면적을 보면 $0.356m^2$으로 최소 면적으로 제시한 $0.371m^2$보다 더 작았다. 그 범위는 작게는 $0.285m^2에서부터 $0.403m^2$까지 큰 차이가 나고 있어 소규모 음식점의 적절한 좌석배치의 치수를 규정하고 계몽할 필요가 있다. 둘째, 소규모 음식점에 사용된 테이블 중 가장 많이 사용된 치수는 4인용 장방형의 $600{\times}900$이었고, 가장 작은 치수는 $440{\times}750$, 여기에서 가장 많이 사용되고 있는 테이블의 치수를 소규모 음식점에서 쓰이는 일반적인 테이블의 치수라 한다면 $600{\times}900$의 크기가 되어, 적어도 이에 준하는 크기가 소규모 음식점의 4인용 장방형 테이블의 치수가 되어야 할 것이다. 셋째, 소규모 음식점에 사용된 의자의 치수 중 자리판의 크기는 $270{\times}270$에서부터 $430{\times}430$까지 매우 다양하게 나타났으며, 그 중 가장 많은 것은 $400{\times}400$이었지만 이 역시 소수였다. 여기에서 가장 많이 쓰이고 있는 $600{\times}900$의 테이블일 경우 자리판의 폭은 400이하가 되어야 옆 사람과의 최소한 여유분을 확보할 수 있을 것이다. 넷째, 소규모 음식점에 사용된 테이블과 의자 자리판사이의 높이는 270-300이 적당한데 조사 결과 270-300보다는 250-260이 더 많았고, 12명을 대상으로 적절성 여부를 설문해본 결과 적절하다고 답했다. 따라서 250-260의 크기도 수용될 수 있다고 본다. 그러나 적절성 여부에 관해서는 보다 깊은 연구가 수반된 후에 논의되어져야 할 것이다.

• 한국생활과학회지
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• 제19권4호
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• pp.655-665
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• 2010

This study analyzed the effects of skinny jean on women's health by questionnaire survey and measuring the pressure experienced under the clothing and participants' subjective view of the pressure level. The average size women in their 20s' waists is 26 inches and so three pairs of jeans were prepared and worn by 4 female participants. A survey was conducted to investigate how often participants wear skinny jeans and whether they had had any feelings of discomfort as a result of this. Participants responded that they hadexperienced middle to high levels of discomfort due to the high pressure inside skinny jeans. For the maximum value of clothing pressures, jean f2 at the part of buttocks showed $48.7gf/cm^2$. The pressure inside the clothing was found to be highest around the buttocks followed by the knees and finally the belly. The mean values of 7 measuring parts are different according to the jean type; f3 $20.8gf/cm^2$ > f2 $16.4gf/cm^2$ > f1 $15.5gf/cm^2$, which is corresponding to the order of pressure sensation, but not corresponding to the order of ease amount of clothing pattern: f2 > f3 > f1. Mean pressure values were also measured according to the body posture: they were found to by highest when sitting on a chair (21.3gf/$cm^2$), second highest when sitting on the floor ($19.2gf/cm^2$) and lowest when standing ($15.0gf/cm^2$). This is not always same to the order of participants subjective perceptions of the pressure, which is, they estimated pressure to be highest when sitting on the floor followed by sitting on a chair and lowest in a standing position.

• 대한인간공학회지
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• 제34권2호
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• pp.179-190
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• 2015

Objective and Background: Due to increase in Musculoskeletal Disorders (MSDs) relating to computer use, a number of ergonomics recommendations have been proposed in order to tackle this problem. However, some of these recommendations have been conflicting. Method: This study was to survey the VDT (Visual Display Terminal) use of office workers. The subjects were 452 workers at 13 places of business and the data were collected by self-administered questionnaire. Results: As a result, prevalence of self-reported MSDs of all VDT workers was 90.2% and shoulder took up 57.0% and neck 38.3% by symptom part of body. The population of computer use of more than 6h/day was 84.5%, and 33.8% also reported using the VDT 2~3h/day without the rest time. Desktop computer users were 95.6%, and a 17-inch monitor accounted for 42.0% among the desktop users. As a result of satisfaction survey on overall computer work, 21.1% of the total respondents said satisfied, desk complaint was about 24.6%, and chair complaint was 33.4%. Despite the importance of computer environment, satisfaction was from fair to uncomfortable. Conclusion and Application: In conclusion, office workers are prone to the MSDs due to their work environment. Additionally, this study found that task was a significant effect for the majority of dependent variables, and therefore, the improvement of computer workstations work environment is urgent, and the improvement of desk height adjustment, chair seat size (length, width), backrest condition, location of keyboard (mouse) and arm rest is required.

• 한국주거학회논문집
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• 제20권1호
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• pp.59-70
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• 2009

The purpose of the study is to suggest the amount of space for each behavior according to the classification of behavior in the housing to plan the optimal floor space of the elderly housing. The method for calculating space for behavior begins with classifying behaviors, identifying them and then taking pictures of the model of elderly people who reproduce each behavior. Based on the pictures, body parts which are necessary for each behavior are assembled and the formula for behavioral space is created. The space for behavior is produced considering the body dimensions of Korean elderly in their sixty's as well as the furniture size and the psychological distance between people. 3D modeling is used to verify the result. Human behaviors can be classified into individual-related, housework-related, family-related, reception-related and other behaviors. These five behaviors are subdivided into more specific behaviors. The area for each specific behavior is calculated with the anthropometric data of the elderly, preferred furniture dimension and psychological area. As a result the required area for specific behaviors is as follows: the behavior of sleeping in a bed needs $4.3m^2$; the behavior of changing clothes on a chair, $1.7m^2$; the behavior of watching TV on the floor $1.3m^2$, the behavior of working and reading using a desk, $2.1m^2$, the behavior of exercise, $2.5m^2$; the behavior of showering on a chair, $1.3m^2$ and showering using a wheelchair, $1.9m^2$; the behavior of toileting using a wheelchair, $2.3m^2$; the behavior of washing up using a wheelchair, $1.9m^2$; the behavior of eating using a table for four persons, $4.4m^2$; the behavior of cooking and washing dishes, $0.9m^2$ per counter-top; the behavior of washing clothes using a washing machine, $0.9m^2$; the behavior of ironing on the floor $1.4m^2$; the behavior of reception(three persons) on the floor considering personal space, $4.0m^2$; the behavior of taking on and off shoes on a chair, $1.3m^2$. The result of the study is utilized as quantitative data to calculate optimal floor space for elderly housing. In addition, qualitative data such as characteristics of housing preference, spacial usage and storage capacity are necessary to produce the floor space which can provide convenient and safe living environment.