• 로봇학회논문지
• /
• 제14권3호
• /
• pp.228-235
• /
• 2019

This paper presents a multiple DoFs (degrees-of-freedom) prosthetic forearm and sEMG (surface electromyogram) pattern recognition and motion intent classification of forearm amputee. The developed prosthetic forearm has 9 DoFs hand and single-DoF wrist, and the socket is designed considering wearability. In addition, the pattern recognition based on sEMG is proposed for prosthetic control. Several experiments were conducted to substantiate the performance of the prosthetic forearm. First, the developed prosthetic forearm could perform various motions required for activity of daily living of forearm amputee. It was able to control according to shape and size of the object. Additionally, the amputee was able to perform 'tying up shoe' using the prosthetic forearm. Secondly, pattern recognition and classification experiments using the sEMG signals were performed to find out whether it could classify the motions according to the user's intents. For this purpose, sEMG signals were applied to the multilayer perceptron (MLP) for training and testing. As a result, overall classification accuracy arrived at 99.6% for all participants, and all the postures showed more than 97% accuracy.

• Journal of Positioning, Navigation, and Timing
• /
• 제8권2호
• /
• pp.49-58
• /
• 2019

A number of techniques have been studied to estimate the position of pedestrians in indoor space. Among them, the technique of estimating the position using only the sensors attached to the body of the pedestrian without using the infrastructure is regarded as a very important technology for special purpose pedestrians such as the firefighters. In particular, it forms a research field under the name of Pedestrian Dead Reckoning (PDR). In this paper, we focus on a method for step detection which is essential when performing PDR using Inertial Measurement Unit (IMU) mounted on a shoe. Many researches have been done to detect the stance phase where the foot contacts the ground. Most of these methods, however, have a way to detect the specific size of the sensor signal and require thresholds for these methods. This has the difficulty of changing these thresholds if the user is different. To solve this problem, we propose a stance phase detection method that does not require any threshold value. It is expected that this result will make it easier to commercialize the technology because PDR can be implemented without user-dependent parameter setting.

• 한국수산과학회지
• /
• 제8권1호
• /
• pp.7-10
• /
• 1975

제주도 고등어 자망어업의 주어기인 1974년 5월 28일부터 8월 31일까지 서귀포와 비양도근해어장에서 고등어 자망어구의 이망율에 관한 시험조업결과는 다음과 같다. 1. $X^2$ t 검정에 의하면 고등어 nylon-monofilament 자망 B형이 nylon-multifilament 자망 A형보다 이망성능이 우위하고 나망율비는 $m_A:m_B=1:1.8$이다. 2. 망목 75mm인 nylon-monofilament 자망 C형, D형이 망목 85mm인 nylon-monofilament 자망 E형 F형 보다 이망성능이 우위하고 이망율비는 $m_E{\cdot}F:m_C{\cdot}D=1:2.8$이다. 3. 망계 굵기가 120tex와 75tex이고 망목이 75m 및 85mm인 C, D, E, F, 형에서는 상호간의 우위는 모두 확인할 수 없었다.

• Journal of Biosystems Engineering
• /
• 제40권1호
• /
• pp.10-18
• /
• 2015

Purpose: The study was conducted to investigate the proper working conditions like the mesh size of the concave and the chaffer angle of the oscillating sieve, and the fan speed of the head-feeding rice combine for foxtail millet harvesting. Methods: The study aimed to determine the harvesting conditions for the rice combine harvester at a 0.5 m/s working speed and at $40^{\circ}$ and $55^{\circ}$ sieve chaffer angles. The harvesting loss of the foxtail millet based on the speed of the fan and the oscillating speed of the sieve was measured at three levels of fan speed and oscillating sieve speed. Results: The threshing rates of different foxtail millet varieties were 64.1~83.5% at a mesh size of 7 mm of the concave. In experimental foxtail millet harvesting, the optimal operating condition of the rice combine harvester included a $40^{\circ}$ sieve chaffer angle and a 4.8 Hz oscillating sieve (cleaning shoe) frequency. The grain loss was found to be lower at a $40^{\circ}$ than at a $55^{\circ}$ sieve chaffer angle. In field harvesting using the combine harvester, the lowest harvesting grain loss rate of the foxtail millet varieties ranged between 0.2~0.5% at a 7 mm mesh concave, $40^{\circ}$ chaffer angle, 4.8 Hz sieve frequency, and a 20 m/s fan speed at an engine speed of 2,000 revolutions per minute (RPM). Conclusions: Findings showed that foxtail millet could be harvested using the combine harvester.

• 한국의류산업학회지
• /
• 제25권1호
• /
• pp.52-61
• /
• 2023

This study aimed to present data for the development of a shoe which is suitable for plus-size men (BMI 25kg/m² or higher) and to analyze the characteristics of each type of foot. The results of the study are as follows. To assess foot shape in relation to weight gain, participants were categorized into normal weight, overweight, and obese weight groups, according to their BMI indexes. Those in the normal weight group exhibited a smaller value than the overweight or obese weight group in all items. As a result of the cluster analysis, by type of foot, of the obese men category, men were classified into four BMI index groups: members of the type 1 group had a BMI index of 157 (18.4% of total sample), while for type 2 the figure was 213 (25.0% of sample), for type 3 it was 259 (30.4%), and for type 4 it stood at 224 (26.3% of total sample). Those from the type 1 group had thin ankles with narrow toes and flattened sides. Type 2 group members had thick ankles with well-developed outer feet and thick sides. Those within the type 3 group had medium-thick ankles with narrow feet but wide inner feet. Finally, those in the type 4 group had feet with a slanted side, as well as thick ankles, wide feet, and flat sides. Among these categories, the type 3 group members indicated the highest distribution.

• 대한치과보철학회지
• /
• 제51권4호
• /
• pp.261-268
• /
• 2013

연구 목적: 본 연구는 납형의 크기 및 형태 변화가 티타늄의 주조성에 어떠한 영향을 미치는지 확인하고자 하였다. 연구 재료 및 방법: 납형의 크기에 따라 Small Pattern군과 Large Pattern군으로 나누었고, 각각 Flat, Semicircular, Horse-shoe 및 V-shape형으로 납형의 형태에 따라 4개의 하위군으로 나누어 총 8개의 군으로 분류하였다. 모든 납형의 주입선은 Runner-bar형으로 하였다. 티타늄 주조 전용 매몰재인 실리카계 매몰재(Rematitan Plus$^{(R)}$, Dentarum, Germany)를 이용하여 매몰하였고, 아크용융 방식의 원심 주조기(Ti Cast Super R$^{(R)}$, Selec, Japan)를 사용하여 주조하였다. 주조성 평가는 완전한 형태로 주조 된 격자의 개수를 척도로 재현 정도를 확인하였다. 통계처리는 SPSS ver. 19.0 for WIN (SPSS. Inc. Chicago, IL, USA)를 사용하였다. 납형의 크기 및 형태에 따른 티타늄의 주조성을 이원변량 분산분석(Two-way ANOVA)을 이용하여 분석하였다. 결과:납형의 평균 재현율은 Small Pattern군은 95.14%, Large Pattern군은 94.30%로 Small Pattern군의 주조성이 유의하게 높았다(P<.05). 납형의 형태 변화에 따른 주조성은 Small Pattern군에서 Semicircular군 133.20개(96.52%), Horse-shoe군 132.40개(95.94%), Flat군 132.00개(95.65%), V-shape군 127.60개(92.46%) 순으로 감소하였다. Large Pattern군은 Flat군 198.60개(95.94%), V-shape군 197.80개(95.56%), Semicircular군 196.40개(94.88%), Horse-shoe군 188.00개(90.82%)순으로 감소하였다. Small Pattern군과 Large Pattern군 모두에서 납형의 형태변화에 따른 주조성은 유의할 만한 차이를 보이지 않았다(P>.05). 결론:주조체의 크기가 작을수록 주조성이 높아짐을 알 수 있었고 형태에 따른 주조성에서는 큰 영향을 받지 않는 것을 알 수 있었다.

• 헤리티지:역사와 과학
• /
• 제56권2호
• /
• pp.124-133
• /
• 2023

국방부 유해발굴단을 통해 발굴된 한국전쟁 전사자 유품의 보존 방법론을 제시하고자 3D 기술의 적용과 가역성 및 안정성이 우수한 보존 재료를 이용해 군화류 2점에 대한 보존처리를 진행하였다. 3D 스캐닝과 모델링을 통해 군화를 신었던 전사자의 발 사이즈를 추정해 볼 수 있었으며, 이를 기반으로 3D 출력 구조체를 이용해 원형을 복원하였다. 원형 복원은 출토 유품의 오염물 제거와 유연제 처리 작업을 거쳐 구조체의 형태로 복원하였으며, 열화되어 찢겨지거나 멸실된 부분은 접합 및 메움처리 후 고색처리를 통해 원형을 복원하였다. 보존처리 후 2종의 군화 모두 밑창과 발등 부분은 고무류, 발등 일부와 발목 부분은 합성가죽류로 제작된 것을 확인할 수 있었으며, 이는 방수 또는 방한의 목적으로 제작되어 1944년에 도입된 모델 Shoe Pac(M-1944, 12-inch) 방한화와 유사한 군화임을 확인하였다. 이러한 결과는 보존처리를 통해 출토된 유품의 제작기법과 재질, 용도 등을 밝혀낼 수 있음을 확인한 연구로서 과학적 보존처리와 3D 기술의 융합적 연구의 중요성을 보여준 사례이다.

• 한국의류산업학회지
• /
• 제22권2호
• /
• pp.202-208
• /
• 2020

This study is to help produce highly comfortable and wearable and footwear based on the establishment of basic data for manufacturing elderly footwear patterns and products. For this, a survey of 207 women in their 20s and 60-70s was conducted to identify the wearing of shoes, inconvenience areas, purchase practices and footwear preferences by age group. The results are as follows. First, the average age of the young female group was 22.5 years old, the elderly female group was 68.8 years old, and the average shoe size was 236.3 mm for the young female group and 238.3 mm for the elderly female group. Second, young women wore shoes for a longer time than elderly women, resulting in swollen and numb legs, hardened soles, uncomfortable toes and sore heels. However, elderly women felt more uncomfortable wearing footwear than young women. They suffered pain in the joint area, heal and toe areas as well as had more toe deformations due to aging. Third, all age groups preferred athletic shoes and loafers as well as purchases from footwear brand stores and department stores. The elderly spent more money on shoes, longer time to buy and valued the feeling of wearing, whereas the young considered design first. Fourth, both age groups prefer low-heels and natural leather, the young preferred to wear various types of shoes; however, the elderly are found to desire shoes that are comfortable and stable in both form and wearing.

• 한국의류학회지
• /
• 제33권5호
• /
• pp.701-710
• /
• 2009

This study was conducted to develop excellent insole with good thermal insulation using new materials. We investigated that aerogel/fiber composite can be used as padding materials of shoes by comparing surface shape, moisture regain, water vapor permeability, thermal insulation and compression rate of insole materials tried with nonwoven fabric padding materials and insole sold in market. The results are as follows. Surface shapes were shown that the most appropriate material for sealing aerogel/fiber composite was high density fabric as per size of particle of aerogel. Moisture regain of aerogel/fabric composite was better than nonwoven fabric padding samples. However, when compared to insole sold in market, its moisture regain was worse than those of insole merchandises. Water vapor permeability was higher in material padded with nonwoven fabric than materials padded with aerogel/fiber composite in all three kinds of sealing fabrics. Thermal conductivity of aerogel/fabric composite was lower than nonwoven fabric material regardless of sealing fabrics. Thermal insulation of aerogel/fiber composite was higher than padding material of nonwoven fabric regardless of sealing fabrics. Compression rate of nonwoven (SP1) was higher than that of aerogel/fiber composite (SP2). Compressive elastic recovery rate of SP1 was also higher than that of SP2, which its compression rate and compressive elastic recovery rate were both poor. As the above result, ultra porous aerogel/fiber composite were proved to be material of good thermal insulation with lower thermal conductivity and also compression rate was proved to be low. Therefore, we can say that aerogel/fiber composite have high possibility to be used as insole materials for cold winter shoes requiring good thermal insulation protection.

• 산업경영시스템학회지
• /
• 제38권4호
• /
• pp.184-192
• /
• 2015

Korea has already entered into an aging society. In recent decades, the health problems for seniors has received considerable interest. We often see the elderly who have been struggled from discomfort or illness of the foot. Those foot related problems mainly cause from the use of improper shoes. Recently, shoe makers sell the shoes for seniors, so called comfort shoes, but the shoes are too expensive for seniors to buy easily. In this paper, we develop cheap insoles for seniors as an alternative of the comfort shoes and suggest the systematic process for the insoles development. This systematic process is as follows: 1) Survey the literature about the market of insole, 2) Investigate the standard size of body and foot for the seniors in Korea, 3) Analyze the customer needs by survey, 4) Study the walking pattern by experiments, and 5) Develop the novel insole for the seniors to relieve the inconveniences related with foot. From the newly developed insoles, the company B gains the sales increasing effect approximately 30% over through the increase in consumer satisfaction and company reputation and secures for intellectual property rights. Using the database from Korea Research Institute of Standards and Science, the reliability of developing technology of the functional insole has been obtained. The seniors are also enable to choose an alternative of comfort shoes for foot health. In the future, the insoles developed from this study have wide applications in the medical, cosmetic fields, and leisure sports fields. Accordingly, it seems to require more systematic studies utilizing Walk Analyzer and Foot Pressure Meter.