• Journal of the Korea Furniture Society
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• v.16 no.2 s.30
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• pp.59-65
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• 2005

As physical condition of students improves, there is a need to develop human body-friendly desk and chair for students. In this study, desks and chairs were manufactured with curved veneer lamination under high frequency heating and pressing, using ten wood species such as Japanese red pine, Korean pine, pitch pine, Japanese larch, yellow poplar, black locust, oak, radiata pine, beech, and birch. The performance of these products were evaluated. The results obtained were summarized as follows; With high frequency heating, the turned lamination of veneers with full size sheet ($3{\times}6\;feet$) prepared by rotary lathe peeling was successfully applied for making the members of desk top, leg frames of desk and chair. Bending strengths of desk tops were relatively greater for yellow poplar, black locust and red pine, which were similar to those of beech and birch. Bending strengths of desk legs were classified into greater species group (red pine, yellow poplar, larch) and lower species group (radiata pine, Korean pine, pitch pine). Compressive strengths of chair legs in parallel direction to the lamination were greater in black locust and larch. On the other hand, differences between outer and inner gap at the top and drawer bottom of desk top were rather larger for the laminations of birch and beech, and less for those of yellow poplar and pitch pine, showing greater stability of open drawer space. In results, yellow poplar, larch, pitch pine and red pine showed good appearance and strength properties at the curved veneer lamination. Accordingly, it was believed that these domestic woods were able to substitute for birch which was being imported for the use of veneer-laminates type furniture.

• Journal of Korean Institute of Industrial Engineers
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• v.35 no.1
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• pp.1-14
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• 2009

The efficiency of transportation requests fulfillment can be increased through extending the problem of vehicle routing and scheduling by the possibility of subcontracting a part of the requests to external carriers. This problem extension transforms the usual vehicle routing and scheduling problems to the more general integrated operational transportation problems. In this contribution, we analyze the motivation, the chances, the realization, and the challenges of the integrated operational planning and report on experiments for extending the plain Vehicle Routing Problem to a corresponding problem combining vehicle routing and request forwarding by means of different sub-contraction types. The extended problem is formalized as a mixed integer linear programming model and solved by a commercial mathematical programming solver. The computational results show tremendous costs savings even for small problem instances by allowing subcontracting. Additionally, the performed experiments for the operational transportation planning are used for an analysis of the decision on the optimal fleet size for own vehicles and regularly hired vehicles.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.4
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• pp.1-7
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• 2019

The customer of massage chair is expanding day by day from middle age to all ages. In 2018, the market size was 700 billion KRW, an increase of 30 times over 10 years. However, most related SMEs suffer from excessive competition by the market monopoly of some major companies. In this situation, in order for a related company to survive, it is necessary to steadily research and develop new products. Founded in 2009, company L produces massage chairs for health and relaxation of customers. L's products use a sound wave vibration module that is favorable for human body, unlike other products that use vibration motor type. However, frequent breakdowns of massage chair due to the vulnerability of plate (leaf) springs, which play an important role in sound wave vibration modules, made sap its competitiveness. In this paper, we propose a method to design desirable plate spring structure by sequentially experimenting with five different plate springs. The results of this study are expected to contribute to improve the quality of plate spring and the reliability of sound wave vibration module. In the future, it is necessary to find a way to use it in the development of foot massage or scalp management device as well as continuous research to find optimal plate spring structure through various analysis.

• The Journal of Korean Academic Society of Nursing Education
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• v.22 no.4
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• pp.485-494
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• 2016

Purpose: The present research is a descriptive study aimed at understanding clinical nurses' Video display terminal (VDT) syndrome and identifying the factors that affect their VDT syndrome. Methods: Data were collected from 239 clinical nurses working in two metropolitan cities. Research tools included subject's VDT syndrome assessing musculoskeletal, ophthalmic, dermal, psychiatric, and whole body syndromes. The data were analyzed using frequency analysis, average and standard deviation, t-test, One-way ANOVA, and multiple regression analysis with the SPSS/WIN 20.0 program. Results: The subjects' VDT syndrome score was 1.34 out of 5. There were significant differences in participating subjects' VDT syndrome, hospital's size, working unit, health status, diagnosis of illness, having an Order Communication System (OCS), having an Electronic Medical Record (EMR) System, continuous VDT working for more than one hour, break time during VDT use, VDT use time, comfort of the chair, adjustability of the height of the chair, size of the VDT's desk, distance between the monitor and the user's eyes, resolution of the monitor, and frequency of eye exercise during VDT use. According to the research, influencing factors on VDT syndrome in clinical nurses included size of the VDT's desk, frequency of eye exercise during VDT use, having an EMR system, break time during VDT use, diagnosis illness, and having an OCS' system. Conclusion: The findings from this study can be used as a basis for future VDT syndrome prevention education and programs for clinical nurses.

• Journal of the Korean Society of School Health
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• v.8 no.2
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• pp.219-232
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• 1995

This study was conducted to examine both usage rate of standard sized desks and chairs for the middle and high school students and pain complant of students who use standard-size desk & chair in Taegu, Korea, by means of questionnaires with 1,201 students of both male and female middle and high schools in Taegu area from March 20 to April 19, 1995. The result of this study is summarized as follows. It was mostly shown that the desks and chairs used by those middle and high school students were 1-3 higher than their standard sizes, and that they also preferred a little higher size with respect to their desired sizes. The rate of students who use the standard size showed that the desk accounted for 30.5%, and chair for 21.0%, that the size bigger than the standard accounted for 61.3%, respectively, and 65.2, and that the size smaller than the standard accounted for 8.2%, respectively, and 13.8%. The using rate of the standard sized for the middle school students indicated that their desk accounted for 44.1%, and their chair for 26.0% which were higher than 16.1% and 14.7% for the high school students. Then, the rate of the male students indicated that their desk accounted for 31.5% and their chair for 24.5% which were higher than 29.6% and 17.6% of the female students. In addition, the using rate of the standard size for the public schools showed that the desk accounted for 34.2% and chair for 24.5% which were also higher than 27.1% and 17.5% of the private schools. It was shown, however, that the using rate of the standard size for both groups was lower. The most inconvenient factor in the usage of their desks appeared in such orders as their wear, narrow drawers, too low height and uneven face, while the factor in their chairs did in such orders as too hard chair body the surface and back part, wear, lower and higher height and narrow width. Their physical pains resulting from usage of those desks and chairs showed that the male and female middle school students' complaint rate of pains in their neck and shoulder accounted for 32.1%, respectively, and 36.0% which were highest, while those high school students' complaint rate in their waist accounted for 37.9%, respectively, and 44.1% which were hight. It was also shown that the bigger their height, the higher their complaint rate of pain in the waist, and that their complaint rate in the shoulder and neck was totally higher. When using the standard-sized desks and chairs, their complaint rate of pain in the shoulder and neck accounted for 25.4%, respectively, and 23.8%. As compared with them, when using the desks or chairs bigger than the standard size, their complaint rate accounted for 31.5%, respectively, and 31.8% which were high while it did 26.5% and 28.9% when using them smaller than the standard size which were also high, the usage of those standard-sized desks and chairs indicated lower complaint rate of pain in their waist than used the desks and chairs bigger or smaller than the standard size. The rate of the middle and high school students who use their standard size is very low and the size of their desks and chairs are quite different from those they hope to use and many students appeal their discomfort with their desks and chairs. Therefore, the school should try to provide the desks and chairs of the various students' standard sizes in consideration of their physical condition and it also should try to get extra desks and chairs of various sizes according to the students' standard size and their preference.

• Journal of the Korean Society of Clothing and Textiles
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• v.17 no.2
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• pp.197-206
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• 1993

We studied relation between the clothing pressure applied by foundations(waist nipper, girdle, body suit) on the waist of bodies and muscular activity, feeling of tightness. The main results were summerized as follows ; 1. Clothing pressure applied by foundations was high in order of girdle>waist nipper>body suit, also clothing pressure was higher back than front and side, sitting on the chair than standing posture, ventral flection than repose. Individual differences, even if size of body was equal, were shown in clothing pressure applied by foundations with subcutaneous fat's amount in measuring region. 2. The muscular activity of rectus abdominis than obliquus externus abdominis was more affected by foundations in all kinds of postures and motions. Amplitude of electromyogram was high sitting on the chair than standing posture, but there was little difference with motion variation. The wearing girdle strongly affected on the muscular activities of rectus abdominis and obliquus externus abdominis as compared with waist nipper and body suit. 3. The value for feeling of tightness by wearing waist nipper was higher than girdle and body suit. Also the case when sitting on the chair and ventral flection, the value for feeling of tightness was high. When the foundations were on the body, most tightened on the region of the body was anterior abdominal region.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.19 no.1
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• pp.16-24
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• 2009

This research aims to measure and analyze the dimensions of typical office chairs and desks sold in domestic market, and to suggest the modifications of national guidelines considering Korean peoples' body characteristics. The scope of this study was limited to the desktop type of computer jobs, excluding laptop environment. The dimensions of 24 different office chairs and 7 tables were measured, and their dimensions were analyzed against the Ministry of Labor (MOL) Notification and Korean Standards (KS). At the same time, the data from the Size Korea was also considered. As a result, the KS guidelines were overall fulfilled by the measured products, while the MOL Notification was not. It was found that the guidelines on the chair height, seat pan depth, lumber support height, and armrest height need to be modified. Some inconsistencies between the MOL Notification and KS were also found. It is suggested that the required dimensions specified by both guidelines should be unified.

• Journal of the Korea Furniture Society
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• v.16 no.1
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• pp.81-89
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• 2005

A chair is a necessary tool in modern life and people spend a lot of time on it. But there Ere so many chairs which the human body size Is not considered that many users usually feel fatigue. The purpose of this study is to analyze the fundamental items human factors engineering which have to be applied to chairs and then to make user choose chairs, considering them as an index. The extent of this study is limited to chairs for office work used for sitting for a long time to work. We also profoundly analyze functional matters of chairs, user's posture and so on. We'll present all suitable factors and the assumed tentative plan by inferring items', the function chairs have coincides with the human body.

• International Journal of Fluid Machinery and Systems
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• v.6 no.4
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• pp.177-187
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• 2013

A scaling method valid for most turbomachines based on first principles is derived. It accounts for axial and centrifugal turbomachines with respect to relative gap width/tip clearance, relative roughness, Reynolds number and/or Mach number for design and off-design operation as well. The scaling method has been successfully validated by a variety of experimental data obtained at TU Darmstadt. The physically based, hence reliable and universal method is compared with previous, empirical scaling methods.

• Korean Institute of Interior Design Journal
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• v.16 no.2 s.61
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• pp.262-269
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• 2007

The blur phenomenon obscuring the boundary between the field of designers and that of users may be the key paradigm in the 21st century. However, we observed a number of chair design cases that could be considered as the results of blur pheonomenon in the furniture design field from mid 1960s. The backgrounds include the repulsion against the uniform functionalism, deliberation on the life in the future and the development of plastic materials and their processing methods. Under such backgrounds, the designers pursued the new and futuristic furniture design. In that process, what is about the "freedom" that the consumers as well as the designers should have in using the furniture was the important concept. This concept enabled the creation of chair design inducing the participation of consumers. They created various kinds of shapes, functions and structures that the consumers became interested in as if they had fun with toy blocks by mainly using the new material "plastic". In a formative aspect, the entire shape is classified into the organic shape and geometric shape. The unit types are divided into two kinds; type that the unit of simple shape is repeated only with size difference and irregular combination type of the units comprised of more than two shapes. In the functional aspect, some cases showed the transformation and expansion of the function more variously. Other cases changed the function of chairs to tables, cabinets, or objects. In the structural aspect, on the basis of the method assembling each unit, one method is to assemble using the hardware and the other is to assemble only with intrinsic units of chair. The chair design created by the blur phenomenon between the designers and the users as described above causes the blur phenomenon between the furniture and the space where the furniture is installed. Accordingly, it is expanding the furniture design sphere including the case that the furniture is not selected as the rifle article depending on the characteristics of interior space but it becomes the element leading the characteristics of space. This study aims to estimate the change of interior space and the furniture that my cause the blur phenomenon by examining the cases above appropriate for the paradigm of the 21st century. Furthermore, this study will enable the discussion oil the directions of future furniture design based on its results.