• Fibers and Polymers
• /
• v.5 no.4
• /
• pp.321-326
• /
• 2004

[ $TiO_2$ ] contents in yarns can influence color yield so that dyeing quality of industrial polyethylene terephthalate (PET) yarns can be improved through the adjustment of $TiO_2$ contents. To evaluate the dyeing performance of color yield, the chips which included the different $TiO_2$ contents of 330,550, and 1,100 ppm respectively were used to produce the yarns of different $TiO_2$ content by a spin-draft machine. The physical and structural properties of the yarns were measured to investigate effect of the $TiO_2$ contents on them. Dye uptake and dyeing rate were also evaluated using a colorimeter to compare the yarns having different TiOz contents. The experimental results showed that there were no appreciable variation in physical and structural properties among the yarn samples and no difference were observed among the dyed fabric samples with regard to dyeing uptake and dyeing rate. However, the color yield of dyed fabrics increased as $TiO_2$ contents decreased in the yarns especially when the fabric samples were dyed to pale shade. The physical reasoning could be proposed on why the yarns having low $TiO_2$ contents appeared to have higher color yield after dyeing.

• The Journal of Korea Robotics Society
• /
• v.17 no.1
• /
• pp.1-7
• /
• 2022

Robots are widely used in industries and services. Traditional robots have been used to perform repetitive tasks in a fixed environment, and it is very difficult to solve a problem in which the physical interaction of the surrounding environment or other objects is complicated with the existing control method. Reinforcement learning has been actively studied as a method of machine learning to solve such problems, and provides answers to problems that robots have not solved in the conventional way. Studies on the learning of all physical robots are commonly affected by noise. Complex noises, such as control errors of robots, limitations in performance of measurement equipment, and complexity of physical interactions with surrounding environments and objects, can act as factors that degrade learning. A learning method that works well in a virtual environment may not very effective in a real robot. Therefore, this paper proposes a weighted sum method and a linear regression method as an effective and accurate learning method in a noisy environment. In addition, the bottle flipping was trained on a robot and compared with the existing learning method, the validity of the proposed method was verified.

• Journal of the Korean Society of Industry Convergence
• /
• v.27 no.3
• /
• pp.701-707
• /
• 2024

Industry 4.0 has brought about significant changes in the roles of workers through the introduction of innovative technologies. In smart factory environments, workers are required to interact seamlessly with robots and automated systems, often utilizing equipment enhanced by Virtual Reality (VR) and Augmented Reality (AR) technologies. This study aims to systematically analyze recent research literature on monitoring the physical and mental states of workers in Industry 4.0 environments. Relevant literature was collected using the Web of Science database, employing a comprehensive keyword search strategy involving terms related to Industry 4.0 and health monitoring. The initial search yielded 1,708 documents, which were refined to 923 journal articles. The analysis was conducted using VOSviewer, a tool for visualizing bibliometric data. The study identified general trends in the publication years, countries of authors, and research fields. Keywords were clustered into four main areas: 'Industry 4.0', 'Internet of Things', 'Machine Learning', and 'Monitoring'. The findings highlight that research on health monitoring of workers in Industry 4.0 is still emerging, with most studies focusing on using wearable devices to monitor mental and physical stress and risks. This study provides a foundational overview of the current state of research on health monitoring in Industry 4.0, emphasizing the need for continued exploration in this critical area to enhance worker well-being and productivity.

• Therapeutic Science for Rehabilitation
• /
• v.11 no.4
• /
• pp.23-39
• /
• 2022

Objective : To summarize clinical and demographic variables and machine learning uses for predicting functional outcomes of patients with stroke. Methods : We searched PubMed, CINAHL and Web of Science to identify published articles from 2010 to 2021. The search terms were "machine learning OR data mining AND stroke AND function OR prediction OR/AND rehabilitation". Articles exclusively using brain imaging techniques, deep learning method and articles without available full text were excluded in this study. Results : Nine articles were selected for this study. Support vector machines (19.05%) and random forests (19.05%) were two most frequently used machine learning models. Five articles (55.56%) demonstrated that the impact of patient initial and/or discharge assessment scores such as modified ranking scale (mRS) or functional independence measure (FIM) on stroke patients' functional outcomes was higher than their clinical characteristics. Conclusions : This study showed that patient initial and/or discharge assessment scores such as mRS or FIM could influence their functional outcomes more than their clinical characteristics. Evaluating and reviewing initial and or discharge functional outcomes of patients with stroke might be required to develop the optimal therapeutic interventions to enhance functional outcomes of patients with stroke.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.12
• /
• pp.2202-2211
• /
• 2010

The wind power prediction system is composed of a meteorological forecasting module, calculation module of wind power output and HMI(Human Machine Interface) visualization system. The final information from this system is a short-term (6hr ahead) and mid-term (48hr ahead) wind power prediction value. The meteorological forecasting module for wind speed and direction forecasting is a combination of physical and statistical model. In this system, the WRF(Weather Research and Forecasting) model, which is a three-dimensional numerical weather model, is used as the physical model and the GFS(Global Forecasting System) models is used for initial condition forecasting. The 100m resolution terrain data is used to improve the accuracy of this system. In addition, optimization of the physical model carried out using historic weather data in Jeju. The mid-term prediction value from the physical model is used in the statistical method for a short-term prediction. The final power prediction is calculated using an optimal adjustment between the currently observed data and data predicted from the power curve model. The final wind power prediction value is provided to customs using a HMI visualization system. The aim of this study is to further improve the accuracy of this prediction system and develop a practical system for power system operation and the energy market in the Smart-Grid.

• Journal of Korean Physical Therapy Science
• /
• v.7 no.1
• /
• pp.353-365
• /
• 2000

The purpose of this study were to compare the lumbar extensor strength between pre op patients group and after 6 weeks post op patients group. To evaluate lumbar extensor strength of total 273 patients with HIVD. Lumbar extensor strength was measured in 151 male patients and 122 female patients(Lumbar extensor strength was measured in 91 PELD patients group and 182 OLM group patients) by Medx lumbar extension machine. Maximum voluntary lumbar extension strength was appear $149.36{\pm}61.92ft$-lbs in pre op of PELD group, $158.47{\pm}54.67ft$-lbs in post op of PELD group and $135.54{\pm}54.24ft$-lbs in pre op of OLM group. $147.19{\pm}52.42ft$-lbs in post op of OLM group in male. Maximum voluntary lumbar extension strength was appear $83.85{\pm}30.22ft$-lbs in pre op of PELD group. $92.99{\pm}28.66ft$-lbs in post op of PELD group and $75.16{\pm}24.98ft$-lbs in pre op of OLM group, $79.88{\pm}25.25ft$-lbs in post op of OLM group in female. Male and female lumbar extension strength was statistically significant difference(P<.05). Lumbar flexion/extension ratio of the two group was 2.14:1 pre op and 2.05:1 post op in lumbar flexion 72 and 0 degree. The ratio of post op group was lesser than pre op group.

• The Journal of Korean Physical Therapy
• /
• v.30 no.5
• /
• pp.159-165
• /
• 2018

Purpose: The aims of this study were to determine if game-based training with constraint-induced movement therapy (CIMT) is effective in improving the balance ability in female patients with a total knee replacement, and to provide clinical knowledge of CIMT game-based training that allows the application of total knee replacement. Methods: Thirty-six patients who had undergone a total knee replacement were assigned randomly to CIMT game training (n=12), general game training (n=12), and self-exercise (n=12) groups. All interventions were conducted 3 times a week for 4 weeks. All patients used a continuous passive motion machine 5 times a week and 2 times a day for 4 weeks. The visual analog scale (VAS), muscle strength of knee flexion and extension, and range of motion (ROM) of knee flexion and extension were assessed, and the functional reach test (FRT), and timed up and go (TUG) test were performed to evaluate the balance ability. Results: All 3 groups showed significant improvement in the VAS, knee flexion and extension muscle strength, FRT, and TUG test after the intervention (p<0.05). Post hoc analysis revealed significant differences in FRT, and TUG of the CIMT game training group compared to the other group (p<0.05). Conclusion: Although the general game training and CIMT game training improved both the knee extension muscle strength and dynamic balance ability, CIMT game training had a larger effect on dynamic balance control.

• Fashion & Textile Research Journal
• /
• v.15 no.3
• /
• pp.444-451
• /
• 2013

This paper surveys the physical properties of aramid and aramid/nylon hybrid air-jet textured yarns(ATY) for protective garments according to wet and dry texturing conditions. Aramid and nylon filaments were used to make two kinds of para-aramid ATY and four kinds of aramid/nylon hybrid ATY with dry and wet treatments. The analyzed physical properties of six specimens (made on the ATY machine) are as follows. The tenacity and initial modulus of aramid and aramid/nylon hybrid ATY decreased with the wetting and breaking strain; however, the yarn linear density of aramid and hybrid ATY increased with wetting treatment. The dry and wet thermal shrinkage of the hybrid ATY increased with wetting. The stability of aramid and hybrid ATY also increased with wetting. The physical properties of core/effect type hybrid ATY showed significantly more change than the core type hybrid ATY and the physical properties of nylon/aramid core/effect hybrid ATY showed significantly more change than the of aramid/nylon core/effect hybrid ATY. A higher bulky and breaking strain of hybrid ATY require ATY processing conditions of nylon on the core part with wetting and aramid on the effect part. ATY processing conditions for nylon and aramid on the core part with wetting are required for a higher tenacity and modulus. ATY processing conditions of nylon and aramid on the core with no wetting are required for a low thermal shrinkage.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.10 no.2
• /
• pp.33-43
• /
• 2004

The purpose of this study was to compare the lumbar extensor strength between before exercise and after 8 weeks exercise in the elderly. To evaluate lumbar extensor strength of total 18 patients (above 59 age) with low back pain or have experienced surgical operation. Lumbar extensor strength was measured in 8 male patients and 10 female patients (9 op group and 9 non-op group) by Medx lumbar extension machine. The data were analyzed with paired t-test compared to muscle strength, with repeated measured ANOVA compared to amount increase of muscle strength, using SPSS ver. 10.0 program. The results of this study were as follows: 1. There were significantly increased total lumbar extension strength was appear $6918.7{\pm}2802.77$ft-lbs in before exercise, $10432.83{\pm}2802.773397.1$ft-lbs in after 8 weeks exercise (p<. 05). 2. There were significantly increased total lumbar extension strength was increased to compared before exercise with after 8 weeks exercise in sex (p<. 05), op/non-op group (p<. 05).

• Asian Spine Journal
• /
• v.12 no.6
• /
• pp.967-972
• /
• 2018

Study Design: Biomechanical study. Purpose: To investigate the relative stiffness of a new posterior pelvic fixation for unstable vertical fractures of the sacrum. Overview of Literature: The reported operative fixation techniques for vertical sacral fractures include iliosacral screw, sacral bar fixations, transiliac plating, and local plate osteosynthesis. Clinical as well as biomechanical studies have demonstrated that these conventional techniques are insufficient to stabilize the vertically unstable sacral fractures. Methods: To simulate a vertically unstable fractured sacrum, 12 synthetic pelvic models were prepared. In each model, a 5-mm gap was created through the left transforaminal zone (Denis zone II). The pubic symphysis was completely separated and then stabilized using a 3.5-mm reconstruction plate. Four each of the unstable pelvic models were then fixed with two iliosacral screws, a tension band plate, or a transiliac fixation plus one iliosacral screw. The left hemipelvis of these specimens was docked to a rigid base plate and loaded on an S1 endplate by using the Zwick Roell z010 material testing machine. Then, the vertical displacement and coronal tilt of the right hemipelves and the applied force were measured. Results: The transiliac fixation plus one iliosacral screw constructions could withstand a force at 5 mm of vertical displacement greater than the two iliosacral screw constructions (p=0.012) and the tension band plate constructions (p=0.003). The tension band plate constructions could withstand a force at $5^{\circ}$ of coronal tilt less than the two iliosacral screw constructions (p=0.027) and the transiliac fixation plus one iliosacral screw constructions (p=0.049). Conclusions: This study proposes the use of transiliac fixation in addition to an iliosacral screw to stabilize vertically unstable sacral fractures. Our biomechanical data demonstrated the superiority of adding transiliac fixation to withstand vertical displacement forces.