• Journal of the Ergonomics Society of Korea
• /
• v.36 no.4
• /
• pp.281-292
• /
• 2017

Objective: This study aims to identify important physical design variables in designing a necklace type wearable device, and to present design guidelines to maximize comfort that a user feels upon wearing the device. Background: Interests in fitness culture and personal health are on the rise recently. In such a situation, demand for necklace type wearable devices is projected to increase a lot, as the devices enable users to use their hands freely and to enjoy various contents through connection with mobile devices. However, the necklace type wearable device's comfort was assessed to have the lowest comfort in a running situation, where human body moves up and down and left and right more than other devices wearable on other human body parts. Therefore, the usability of a necklace type wearable device was low. In this regard, studies on identification of the variables affecting user comfort upon wearing a necklace type wearable device and on physical design direction maximizing comfort and usability are needed. Method: A pretest and a main test were carried out to draw the direction of necklace type wearable device design. In the pretest, wearing evaluation on the diverse types of devices released in the market was conducted to draw physical design variables of the devices affecting comfort. Furthermore, variables significantly affecting the comfort of a device were selected through an analysis of variance (ANOVA). In the main test, anthropometry was performed, and information on anthropometric items corresponding to the design variables selected in the pretest was acquired. Based on the pretest results and the anthropometric information in the main test, the present study produced design guidelines maximizing the comfort of a necklace type wearable device with regard to major design variables upon dynamic tasks. Results: According to the pretest results, the variables having effects on comfort were the angle of side points, width, and height. Due to interactions between variables, those need to be simultaneously considered upon designing a device. Upon dynamic tasks, the angle of side points and width of a device was designed to be smaller than mean angle of the trapezius muscle and neck width, and thus attachment to human body was high. As height was designed to be larger than mean neck front and rear point width, comfort was higher due to feeling of stability. Conclusion: Because user sensitivity to comfort was high at human body's inflection points, a device needs to be designed for users not to feel high pressure on specific body parts with the device fitting human body shape well. A design considering user's situation is also required in further studies.

• Journal of Fashion Business
• /
• v.15 no.1
• /
• pp.103-114
• /
• 2011

This study is to provide basic information on clothing fitness necessary to develop apparel products for Korean companies that want to enter or have already made inroads into the Chinese market. In an effort to serve this purpose, a standard upper torso body model for Chinese women was established by applying the Rohrer Index and Size Designation of Clothes - Women of GB/T 1335.2-1997 to Chinese women in their 20s to determine body types and its characteristics. First, according to the result of applying the Rohrer Index to categorize body types, Type 1 showed the longest vertical body length and a short horizontal length with the lowest degree of flatness. Type 2 was a standard body type with a height of 158.73cm, weight of 53.02kg and the Rohrer Index of 1.32. Type 3 had a thick and flat body shape that had the highest degree of flatness and the shortest vertical length in its upper torso among all three types of body. Second, F-test was conducted on 4 distinctive body types obtained from comparing obesity scores to verify differences in body shapes for different degree of obesity. The test result indicated significant differences in 3 of the 4 body types and showed different structural components for different degree of obesity. Third, the result of comparing correlational distributions of body types and height range, and body types and degree of obesity for all and specified age groups revealed that about 33.30% of the body types appeared in Type2-A followed by 20.18% in Type1-A, 18.40% in Type2-Y and 7.91% in Type1-Y respectively. Body types and degree of obesity for two different age groups were most frequent in Type2-A. For the group of young women in their early 20s appeared the most in Type2-A, Type1-A, Type2-Y and Type 1-Y respectively and young women in late 20s were frequent in the order of Type2-A, Type2-Y, Type1-A and Type1-Y.

• Journal of the Ergonomics Society of Korea
• /
• v.34 no.5
• /
• pp.541-548
• /
• 2015

Objective: We introduce a hand gesture segmentation method using a wrist-worn wearable device which can recognize simple gestures of clenching and unclenching ones' fist. Background: There are many types of smart watches and fitness bands in the markets. And most of them already adopt a gesture interaction to provide ease of use. However, there are many cases in which the malfunction is difficult to distinguish between the user's gesture commands and user's daily life motion. It is needed to develop a simple and clear gesture segmentation method to improve the gesture interaction performance. Method: At first, we defined the gestures of making a fist (start of gesture command) and opening one's fist (end of gesture command) as segmentation gestures to distinguish a gesture. The gestures of clenching and unclenching one's fist are simple and intuitive. And we also designed a single gesture consisting of a set of making a fist, a command gesture, and opening one's fist in order. To detect segmentation gestures at the bottom of the wrist, we used a wrist strap on which an array of infrared sensors (emitters and receivers) were mounted. When a user takes gestures of making a fist and opening one's a fist, this changes the shape of the bottom of the wrist, and simultaneously changes the reflected amount of the infrared light detected by the receiver sensor. Results: An experiment was conducted in order to evaluate gesture segmentation performance. 12 participants took part in the experiment: 10 males, and 2 females with an average age of 38. The recognition rates of the segmentation gestures, clenching and unclenching one's fist, are 99.58% and 100%, respectively. Conclusion: Through the experiment, we have evaluated gesture segmentation performance and its usability. The experimental results show a potential for our suggested segmentation method in the future. Application: The results of this study can be used to develop guidelines to prevent injury in auto workers at mission assembly plants.

• Journal of Korean Society of Transportation
• /
• v.33 no.4
• /
• pp.348-356
• /
• 2015

In 2026, in ten years from now, Korea is expected to enter into a super aged society. By facing this social phenomenon, analyzing the elderlies and preparing measures are needed among society. In the transportation field, the traffic accidents which are related to the elderly pedestrians have drastically increased so that R&D projects and policy supplementations are introduced. However very few base studies on which focused on the behavior, capability, impact factors analysis of for elderly pedestrians are conducted. To determine the walking capability, this study divided the walking capability into 3 three categories - general, health and exercise. It carries out the comprehensive survey targeting 52 elderlies with the average age of 72.6 years and this survey is made up of total 12 factors in the 3 three categories. This survey also is conducted with various measuring devices and methods such as interview, National Fitness Award, SPBB, Cybex and the like for. From the 12 detailed factors, the general factors such as age, physical shape and so forth have little impact on the walking speed. However the factors that have the greatest impact on the walking speed are extensor muscle on lower limbs in the health factors and balance, coordination, and SPPB in the exercise factors. With these results, this study develops the independent walking model which can measure the walking capability of the elderly people. The developed model is expected to be utilized as the base study for elderly's walking patterns in the transportation field by examining the walking capability of the older people.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.27 no.3_4
• /
• pp.407-417
• /
• 2003

The purpose of this study is to develop designs and patterns of a functional brassiere. For this purpose, women who have protruding and drooping breasts with 75B for their brassiere size were sampled. The fitting test for the fitness and function of test brassiere and control brassiere were carried out twice and compared the results from the both in terms of front, rear and side looks. The results of this study can be summarized as follows; 1. The results from measuring the level of sag and spread, and volume and protrusion of breasts shows that there are some distinctive differences in the measurements before and after wearing the test brassiere and the test brassiere is proved to be very effective in correcting breasts' shapes. 2. Front look: Since the two front cutting lines of the test brassiere served to have the curved main part pressing against the breasts, it could support breasts to more than satisfactory level. In addition, upperline panel and side panels of the test brassiere were found to have the upperline of the upper cup pressed against the breasts and at the same time it pressed and gathered the flab around upper part of the breasts and armpits that helped to rearrange the shape of the breasts. It is also proved that the two-pieced test brassier was found to be more functional in supporting the lower cup of the breasts. 3. Rear look: The test brassier was made up of two wide U-shaped wings with 2.5cm tape on its lower sides. Each wing has 4 lines and 3 hems (5.5cm). For this reason, the test brassiere was tighter and better fitted on its back. 4. Side look and entire look: The wings of the test brassiere might look wider than that of the control brassier which has conventional straight-shaped wings, but it was analyzed that the test brassiere held the upper and lower sides of the wings more effectively to be more pressed against the breast. Therefore, the test brassiere scored higher in terms of adjusting to body movements, while the control brassiere looked better in overall terms. 5. The functional brassier fur protruding and drooping breasts developed from the experiments of this study is a full side stretch brassiere which covers the entire breasts satisfactorily. The pattern drafting methods are suggested in to .

• Journal of the Korea Society of Computer and Information
• /
• v.25 no.6
• /
• pp.155-164
• /
• 2020

In this paper, we proposed the dimensional system and pattern of middle-aged women's rashguard swimwear for breast cancer patients. First, a survey of 37 breast cancer patients was conducted to determine the preferred swimsuit design for breast cancer patients. According to a survey of breast cancer patients, a rashguard swimwear with a low-exposure chest was designed. It has a pocket shape in which the cap is easy to insert and the cap is fixed. Second, we developed a dimensional system for swimsuits for breast cancer patients. Using direct measurement data from Size Korea for 1,625 women aged 30 to 69, 17-sizes for breast cancer patient's swimsuits were set through cross-analysis of major dimensions, with a coverage rate of 74.3%. It also extracted a standard size of bust circ. 90cm, hip circ. 95cm, and trunk circ. 150cm. Third, we developed a pattern for the central size of the swimsuit for breast cancer patients. For this purpose, we first produced the first central size pattern, and then completed the pattern after modifying it through the second and third wearing experiments. Experimental suits were produced at each pattern-making stage to evaluate wearing fit and motion suitability. Finally, the reduction rate of each dimension item for optimal pattern production was obtained, and the lashguard swimwear pattern for breast cancer patients was developed.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.36 no.4
• /
• pp.213-220
• /
• 2023

This paper presents a model simulating the folding process and collision dynamics of "ddakji", a traditional Korean game played using paper tiles (which are also referred to as ddakji). The model uses two A4 sheets as the base materials for ddakji. The folding process involves a series of boundary conditions that transform the wing part of the paper structure into a twisted configuration. A rigid plate boundary condition is also adopted for squeezing, establishing the shape and stress state of the game-ready ddakji through dynamic relaxation analysis. The gaming process analysis involves a forced displacement of the striking ddakji to a predetermined collision position. Collision analysis then follows at a given speed, with the objective of overturning the struck ddakji--a winning condition. A genetic algorithm-based optimization analysis identifies the optimal collision conditions that result in the overturning of the struck ddakji. For efficiency, the collision analysis is divided into two stages, with the second stage carried out only if the first stage predicts a possible overturn. The fitness function for the genetic algorithm during the first stage is the direction cosine of the struck ddakji, whereas in the second stage, it is the inverse of the speed, thus targeting the lowest overall collision speed. Consequently, this analysis provides optimal collision conditions for various compression thicknesses.

• Korean Journal of Environment and Ecology
• /
• v.25 no.5
• /
• pp.787-798
• /
• 2011

An arboretum is defined as a collection of facilities that conserve plant species by surveying, collecting, and proliferating and preserving the plants in nature, perform diverse researches on plants and display the plants in exhibition spaces or outdoors as well as provide the public with educational programs and refreshment spaces according to the laws concerned. The public, however, recognizes the exhibition and education functions on plants of arboretum more importantly compared with the roles to survey, collect, and proliferate plants as regulated by the laws. In particular, arboretum plays a role to offer a pivotal educational place in urban area where the public can obtain an hands-on experience and understanding on a wide range of plant species and natural environment. The study aims to estimate the non market environmental values of Daegu Arboretum operated by Daegu Metropolitan City government by using the Contingent Valuation Methods (CVM), which yields the current monetary estimates for the arboretum. The value estimation was undertaken by using the Double-Bound Dichotomous Choice (DBDC) method, and each estimated value was derived from respective functions based on a logit distribution known to include relatively stable estimates according to the shape of the distribution. Considering the statistical fitness test results, the author estimated the amounts of the Willingness To Pay (WTP) such as mean WTP of 12,718 KRW, median WTP of 11,033 KRW, and truncated mean WTP of 11,468 KRW, which represented the annual recreational values per a person visiting Daegu Arboretum respectively. The analysis showed that Daegu Arboretum created the annual environmental values which were estimated to be approximately 16 to 19 billion KRW. The study also has an implication that the valuation method for the environment of Daegu Arboretum may be effectively applied for estimating the values of other types of environmental goods by altering the locations or goods to be analyzed.

• Journal of Korean Society of Forest Science
• /
• v.112 no.4
• /
• pp.417-425
• /
• 2023

The aim of this study was to derive stem taper equations for Quercus acuta, one of main evergreen broad-leaved tree species found in warm temperate regions, and to prepare a stem volume table using those stem taper equations. A total of 688 individual trees were used in the analysis, which were collected from Jeonnam-do, Gyeongnam-do, and Jeju-do. The stem taper models applied to derive the stem curve pattern were the Max and Burkhart, Kozak, and Lee models. Among the three stem taper models, the best explanation of the stem curve shape of Q. acuta was found to be given by the Kozak model, which showed a fitness index of 0.9583, bias of 0.0352, percentage of estimated standard error of 1.1439, and mean absolute deviation of 0.6751. Thus, the stem taper of Q. acuta was estimated using the Kozak model. Moreover,thestemvolumecalculationwasperforme d by applying the Smalian formula to the diameter and height of each stem interval. In addition, an analysis of variance (ANOVA) was conducted to compare the two existing Q. acuta stem volume tables (2007 and 2010) and the newly created stem volume table (2023). This analysis revealed that the stem volume table constructed in the Wando region in 2007 included about twice as much as the stem volume tables constructed in 2010 and 2023. The stem volume table (2023) developed in this study is not only based on the regional collection range and number of utilized trees but also on a sound scientific basis. Therefore, it can be used at the national level as an official stem volume table for Q. acuta.