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W. Lee

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13 records found

Conference paper (2020) - Wonsup Lee, Jin-Gyun Kim, Johan M.F. Molenbroek, Richard H.M. Goossens, Heecheon You
A 3D head and face scan data can be usefully applied in the ergonomic design of a wearable product such as an oxygen mask or a virtual reality (VR) headset to support the safety as well as comfort for a certain amount of a target population. This study is aimed to develop analysis and design methods of an ergonomic facial wearable products (e.g., pilot oxygen mask, VR headsets) based on numerous 3D face scan data (366 faces and 2,299 heads) through the template registration and the finite element (FE) analysis methods to predict the contact pressure between the face and a product. The application of the FE analysis on numerous 3D images to find an optimal form of a product is a novel approach in product design. The proposed methods on contact pressure analysis could be usefully applied for wearable products, which fit body parts. ...
Conference paper (2019) - Lyè Goto, Toon Huysmans, Wonsup Lee, Johan F. M. Molenbroek, Richard Goossens
In Ergonomic product design, designers need to translate anthropometric data of the target population into product dimensions or sizing systems. Currently, sizing systems are often based on traditional anthropometric data and generally use the variation of one or two key body dimensions directly related to the product. For products that need to closely fit a certain part of the body it is relevant to incorporate multiple key dimensions. This can be realized by a multivariate approach such as a Principal Component Analysis. Over the past decades, there has been an increase in incorporating 3D imaging in anthropometric surveys. In order to integrate the use of 3D anthropometry in product sizing, representative models are used to visualize the variability of the target population. For the development of a ventilation mask for children, this study compares representative models of 3D faces based on a bivariate, multivariate and shape based analysis of 303 children's faces. ...
Journal article (2018) - Wonsup Lee, Xiaopeng Yang, Daehen Jung, Seikwon Park, Heeeun Kim, Heecheon You
A revised pilot oxygen mask design was developed for better fit to the Korean Air Force pilots’ faces. The present study compared an existing pilot oxygen mask and a prototype of the revised mask design with 88 Korean Air Force pilots in terms of subjective discomfort, facial contact pressure, and slip distance on the face in high gravity. The average discomfort levels, facial contact pressures, and slip distance of the revised mask were reduced by 33%–56%, 11%–33%, and 24%, respectively, compared to those of the existing oxygen mask. The mask evaluation method employed in the study can be applied to ergonomic evaluation of full- or half-face mask designs. ...
Journal article (2018) - Wonsup Lee, Baekhee Lee, Xiaopeng Yang, Hayoung Jung, Ilgeun Bok, Chulwoo Kim, Ochae Kwon, Heecheon You
The present study developed a sizing analysis system for head-related product designs based on the Civilian American and European Surface Anthropometry Resource (CAESAR) database of North Americans. A total of 2299 heads in the CAESAR database were manually edited and 26 anthropometric landmarks were marked on the edited 3D heads to measure 30 anthropometric dimensions related to head-related product designs. The 3D anthropometric sizing analysis system (3D-ASAS) developed in the study provides analysis functions of a sizing system and representative face models by considering a target product, a target population, the number of size categories, and key anthropometric dimensions based on the CAESAR head measurements. Further research to reduce the efforts of manual editing and landmarking of 3D body scan data is discussed for efficient application of the 3D-ASAS to the design process of various wearable products. ...
Journal article (2017) - Joonho Chang, Kihyo Jung, Wonsup Lee, Heecheon You
The present study developed and tested a new usability evaluation method which considers natural product-use motions. The proposed method measures both natural product-use motions (NMs) and actual product-use motions (AMs) for a product using an optical motion capture system and examines the usability of the product based on motion similarity (MS; %) between NMs and AMs. The proposed method was applied to a usability test of four vacuum cleaners (A, B, C, and D) with 15 participants and their MSs were compared with EMG measurements and subjective discomfort ratings. Cleaners A (44.6%) and C (44.2%) showed higher MSs than cleaners B (42.9%) and D (41.7%); the MSs mostly corresponded to the EMG measurements, which could indicate that AMs deviated from NMs may increase muscular efforts. However, the MSs were slightly different from the corresponding discomfort ratings. The proposed method demonstrated its usefulness in usability testing, but further research is needed with various products to generalize its effectiveness. ...
Journal article (2017) - Amir Tjolleng, Kihyo Jung, Wongi Hong, Wonsup Lee, Baekhee Lee, Heecheon You, Joonwoo Son, Seikwon Park
An artificial neural network (ANN) model was developed in the present study to classify the level of a driver's cognitive workload based on electrocardiography (ECG). ECG signals were measured on 15 male
participants while they performed a simulated driving task as a primary task with/without an N-back task as a secondary task. Three time-domain ECG measures (mean inter-beat interval (IBI), standard deviation of IBIs, and root mean squared difference of adjacent IBIs) and three frequencydomain ECG
measures (power in low frequency, power in high frequency, and ratio of power in low and high frequencies) were calculated. To compensate for individual differences in heart response during the driving tasks, a three-step data processing procedure was performed to ECG signals of each participant: (1) selection of two most sensitive ECG measures, (2) definition of three (low, medium, and high) cognitive workload levels, and (3) normalization of the selected ECG measures. An ANN model was constructed using a feed-forward network and scaled conjugate gradient as a back-propagation learning rule. The accuracy of the ANN classification model was found satisfactory for learning data (95%) and testing data (82%). ...
Journal article (2017) - Wonsup Lee, Xiaopeng Yang, Sunghye Yoon, Baekhee Lee, Eunjin Jeon, Heeeun Kim, Heecheon You
This study aimed to compare a three-dimensional (3D) semiautomatic measurement protocol (3D-SAMP) that measures hand dimensions using a plaster hand and a 3D scanner with the conventional direct measurement protocol (DMP). An experiment was conducted to measure 52 dimensions of one hand by 20 measurers with three repetitions. The locations of landmarks attached to the plaster hand were automatically identified and then measurements of the hand dimensions were automatically extracted in the 3D-SAMP. Significant measurement differences with a range of 2.1 to 4.4 mm between the 3D-SAMP and the DMP were observed in 13 out of the 52 dimensions, and the 3D-SAMP showed better reliability than the DMP in terms of intra- and intermeasurer variability. The 3D-SAMP was found significantly faster and easier in hand measurement than the DMP (11.1 ± 3.5 min for 3D-SAMP and 17.8 ± 4.5 min for DMP; 5.2 ± 0.8 for 3D-SAMP and 4.3 ± 0.8 for DMP using a 7-point scale with 1 for very dissatisfied and 7 for very satisfied for ease of measurement) when fabrication (about 1 hr 10 min) and scanning (3 min) of a plaster hand were not considered. The proposed 3D-SAMP is applicable only to plaster hands available in hand measurement. ...
A sizing system of a multiple-size product have been conventionally generated based on anthropometric size of a human body part. But a product which fit to a complex-shaped body part such as the face need to have a sizing system generated with consideration of body shape characteristics. This study applied template registration and machine learning clustering methods in order to make a sizing system which can consider variations of size and shape of the face. A hybrid approach using the bounded biharmonic weights (BBW) and non-rigid iterative closet point (ICP) registration methods was applied in this study to generate template-registered face images. Then, the Self-Organizing Map (SOM), a type of artificial neural network model for large-data clustering was used in order to cluster the template-registered face images into multiple shape categories. The proposed methods can be usefully applied in design of a facial wearable product such as face mask. ...
3D scan images have been successfully applied in ergonomic product design. Features of human body parts (e.g., landmarks, measurements, curvatures, surfaces, volumes) extracted from 3D body scan images can be used to analyze variations of the size and shape of human bodies. The information of size and shape variations can be
applied in product design to support technical ideas regarding accommodation, tolerance, and adjustability. This study is aimed to briefly introduce a few analysis methods of
body shape variation using 3D facial scan images of Dutch children in order to acquire useful features for the design of a children's facial mask. ...
Conference paper (2016) - L Goto, W Lee, Y Song, JFM Molenbroek, RHM Goossens
Designers integrate the use of anthropometric data in their design process to optimize the usability and functioning of a product while improving comfort and safety. Information regarding the size and shape of the human body are important when it comes to designing products in general, and especially where fit is essential such as helmets, ventilation masks and goggles. Advances in 3D imaging technologies have facilitated the collection of these measurements and shapes. In addition, because of the high capturing speed, these technologies have great advantage when gatheringanthropometric data of elderly or children.In order to design a ventilation mask for young children an anthropometric survey was conducted to map the shape of the head and face of children between the ages of 0.5 to 7 years old. A total of 307 children were measured through a combination of traditional anthropometric measurements and 3Dscan-derived measurements. The facial measurements of children 6 years of age were analysed and in order to map the variation between them, a Principal Component Analysis (PCA) was conducted. The results of the PCA could give designers an insight into the measurements that explain thevariation in children’s faces. ...
Journal article (2016) - Wonsup Lee, Xiaopeng Yang, Hayoung Jung, Heecheon You, Lyè Goto, Johan Molenbroek, Richard Goossens
Abstract: 3D human body scan datasets have been collected and various techniques of post-processing, size and shape analysis, and applications in product design have been introduced. This paper is aimed to introduce techniques and cases of head-product design studies based on massive 3D head scan datasets. 3D scan datasets of the head, face and ear were collected and post-processed by editing, landmarking, alignment and measurement. For useful application of the 3D head scan datasets in head-product designs, we applied several analysis techniques such as development of a sizing system, selection of representative models, analysis of shape variation based on template-registered 3D scans and analysis of virtual fit. This paper can help understand an overview of techniques regarding massive 3D scan datasets and their applications to ergonomic product design. ...
Journal article (2016) - Minseok Jeong, Chuneun Yang, Heecheon You, Kwangae Park, Wonsup Lee
An online suit-customizing system for the special accessibility needs of wheelchair users should be developed because the demand for business suits by wheelchair users involved in economic activities has increased. This study develops a user interface an online customizing system for men's suits specialized for wheelchair users. This study used a five-step approach: (1) search for online men's suits customizing system in web porter sites, (2) select three sites based on three terms, (3) heuristic testing with five web specialists, (4) development of a system user interface based on suggestions for improvement from the heuristic test, (5) usability testing of the user interface prototype by 10 disabled men in wheelchairs. The interface of Company S had high ratings on interactivity, accessibility, informativeness, and consistency in the heuristic test results; subsequently, a user interface was developed based on suggestions for improvement from the heuristic test. This online user interface for customizing men's suits provides better usability to wheelchair users than existing online interfaces aimed at the non-disabled and disabled; consequently, this study contributes to the commercialization of an online customizing system for men's suits specializing in serving wheelchair users. ...
Journal article (2016) - Wonsup Lee, Hayoung Jung, Ilgeun Bok, Chulwoo Kim, Ochae Kwon, Teukgyu Choi, Heecheon You
Detail anthropometric dimensions and a 3D shape of the outer-ear are applicable to design ear-related products such as an earphone. However, 3D scanning of the ear part is quite difficult due to a complex shape of the ear, also detailed ear dimensions which are needed to be measured for earphone design were not identified in previous studies. This study collected 3D scan images of the whole outer-ear from 100 Korean participants (50 females and 50 males) aged 20 to 59, then measured their detailed ear dimensions for earphone design. The pinna part was directly 3D scanned; and complex shape of the concha and acoustic canal parts were cast by applying an ear casting tool, then the cast was scanned in 3D. 13 ear dimensions were measured by applying an ear measurement system coded using Matlab. Both 3D ear scans and ear measurements were applied to design some earphone parts (earphone-head, ear-band, ear-tip) in this study. ...