• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.178-186
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• 2015

Endurance time is very important indicator to estimate muscle fatigue. In the case of measuring endurance time directly, it is dangerous for subject to perform a test until the point of failure to main time force. Therefore, this paper presents the model to estimate endirance time using indirect measurements such as personal factors and anthropometrical data. Previous studies had shown that personal factors such as gender and age were not related to endurance time, but recently studies have shown that it is estimated by using independent variable or predictor such as GTA (Gravitational Torque of the horizontal, stretched arm) and MVC (Maximum Voluntary Contraction). The present study investigated variables to estimate endurance time using personal factors and anthrometrical data during isotonic contractions. Twenty five healthy subject volunteered for this study, and performed three test sessions of isotonic contraction exercises at 10~50% respectively. Afterward the correlation coefficient and p-values were compared among regression models using personal factors and anthropometrical data. The results demonstrated that multi-regression model had significant coefficient of correlation, and was useful estimate endurance time.

• Journal of the Korean Society of Clothing and Textiles
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• v.26 no.1
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• pp.74-82
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• 2002

The present study is aimed to investigate the effect of the safety hat on the balance of body temperature by observation of the physiological response under hot working environment. The experiment was carried out in a climate chamber of 3$0^{\circ}C$, 50%RH for 70 minutes. To compare the two kinds of safety hat, 5 healthy male subjects worn safety hat without hole (called 'without hole') or safety hat with hole (called 'with hole') according to a randomized cross-over design. The main results of this study are as fellows: Rectal temperature and heart rate were significantly lower level in 'with hole'than in 'without hole'. The mean skin temperature was significantly higher in 'without hole'than in 'with hole'. Blood pressure were significantly low in 'with hole'. Sweat rate which was measured by weight loss before and after experiment was higher in 'without hole'. In subjective ratings, subjects replied more hot, more uncomfortable and more wet, they felt more fatigue in condition of 'without hole'. Work ability which was measured by a grip strength dynamometer was higher in 'with hole'. Safety hat which can be used for safety of the brain in work place is meaningful device of behavioral thermoregulatory response under the hot working environment. The safety hat which is designed for proper ventilation and hygiene can maintain the homeostasis of body temperature by releasing body temperature efficiently.

• Journal of Hospice and Palliative Care
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• v.16 no.4
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• pp.205-215
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• 2013

Most terminally ill cancer patients experience various physical and psychological symptoms during their illness. In addition to pain, they commonly suffer from fatigue, anorexia-cachexia syndrome, nausea, vomiting and dyspnea. In this paper, I reviewed some of the common non-pain symptoms in terminally ill cancer patients, based on the National Comprehensive Cancer Network (NCCN) guidelines to better understand and treat cancer patients. Cancer-related fatigue (CRF) is a common symptom in terminally ill cancer patients. There are reversible causes of fatigue, which include anemia, sleep disturbance, malnutrition, pain, depression and anxiety, medical comorbidities, hyperthyroidism and hypogonadism. Energy conservation and education are recommended as central management for CRF. Corticosteroid and psychostimulants can be used as well. The anorexia and cachexia syndrome has reversible causes and should be managed. It includes stomatitis, constipation and uncontrolled severe symptoms such as pain or dyspnea, delirium, nausea/vomiting, depression and gastroparesis. To manage the syndrome, it is important to provide emotional support and inform the patient and family of the natural history of the disease. Megesteol acetate, dronabinol and corticosteroid can be helpful. Nausea and vomiting will occur by potentially reversible causes including drug consumption, uremia, infection, anxiety, constipation, gastric irritation and proximal gastrointestinal obstruction. Metoclopramide, haloperidol, olanzapine and ondansetron can be used to manage nausea and vomiting. Dyspnea is common even in terminally ill cancer patients without lung disease. Opioids are effective for symptomatic management of dyspnea. To improve the quality of life for terminally ill cancer patients, we should try to ameliorate these symptoms by paying more attention to patients and understanding of management principles.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1309-1321
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• 2023

This study was conducted by dividing L-arginine intake group (n=14) and placebo group (n=14) to investigate the effect of L-arginine intake on athletic performance, lactate, lactate dehydrogenase, and ammonia of men's college Taekwondo Kyorugi players during 8-week of intensive winter training. The L-arginine intake group consumed a total of 3 g, including 1 g for breakfast, 1 g for lunch, and 1 g for dinner, and the placebo group consumed maltodextrin in the same way. The 8-week winter training program was conducted at 70-90%HRR (heart rate reserve). Two-way repeated measures ANOVA was used for the interaction between the L-arginine intake group and the placebo group of the measured data, paired t-test was used for the difference between the periods within the group, and the difference between groups was analyzed using independent t-test. As a result, there was an interaction between groups in the average number of kicks among the performance ability through the TAAA (Taekwondo-specific aerobic anaerobic agility) test , and the main effect between groups was shown (p<.05). In addition, there was an interaction between groups and time in the kick fatigue index (p<.05). In lactate, the time-interaction were shown (p<.05) and interaction effects and inter-time main effects were observed in lactate dehydrogenase (LDH)(p<.05). In the case of ammonia, the interaction effect between the group and time was shown (p<.05). These results show that L-arginine intake can play a positive role in quickly synthesizing nitric oxide in blood vessels and expanding blood vessels to quickly remove fatigue-causing substances in the body for athletes who are easily exposed to fatigue after high-intensity training for male college Taekwondo Kyorugi players. Therefore, it is recommended to take L-arginine as a way to improve the performance of high-intensity elite Taekwondo Kyorugi players and recover from fatigue.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.7 no.2
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• pp.55-62
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• 2013

The exoskeleton robot to assist walking of hemiplegia patients or disabled persons has been studied in this paper. The exoskeleton robot with degrees of freedom of 2 axis has been developed and tested for joint motion. The obtained EMG signal from normal person was analyzed and the control signal was extracted from it for convenient and automotive performance of assistance robot to help hemiplegia patient walks as normal person does. the purpose of using FES(Functional Electrical Stimulation) for hemiplegia patient's walk is to restore damaged body function by this, but this could give fatal electrical shock to patients by wrong use or cause quick fatigue in muscle by continuous stimulation. The convenient movement of hemiplegia patients with minimum muscle fatigue was looked possibly by operation of assistance robot exoskeleton using control signal. and the walking assistance exoskeleton robot seemed works more efficiently than using FES stimulator. The experiment in this study was performed based on usual motion in our life like walking, standing-up, sitting-down, and particularly feedback control system using Piezo sensor along with button switch was applied for smooth swing motion in walking. The experiment also shows that hemiplegia patients can move conveniently by using electromyogram signal of healthy leg for the operation signal of assistance robot system attached at damaged symmetrical leg.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.1
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• pp.118-124
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• 2017

To investigate and analyze the cause of the failure of the connecting rod bolt and the crank pin bearing bolt of the diesel engine of this study, the following results were obtained through site surveying, the investigation of literature referring to similar failures, testing and inspection of the fracture surface, and the experience of the researchers. The fractured crank pin bearing bolt of the diesel engine is estimated to be damaged later than the connecting rod bolt. From the shape of fracture surface, it is evident that the failed connecting rod bolt is fractured by fatigue failure due to abnormally repeated loads (e.g. loosening of the connecting bolt, etc.), and is not failed by brittle fractures due to the impact load. The surface of the U-nut on the fractured connecting rod bolt has been worsening due to the improper use of lubricant (agent for prevention of thread fixing) and no usage of separating the each connecting rod on each cylinder. Moreover, there is the possibility that those poor surface conditions of the fractured connecting rod bolt have affected the failure of the connecting rod bolt of the main engine. And it could be assumed that the mechanical characteristic and manufacturing process of the failed connecting rod bolt and crank pin bearing bolt, which were made by a domestic company, conform to the design requirements for those bolts.

• The Journal of the Korea Contents Association
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• v.18 no.4
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• pp.586-600
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• 2018

The purpose of this study attempted to collect basic data for development of an integrated self-management program for cancer survivors who completed cancer treatment. Self-management programs are divided into symptom management and physical activity management. Symptom management includes fatigue, sleep disturbance, pain, depression and anxiety. PubMed, CINAHL and EMBASE were used for searching guidelines. Based on the guideline quality evaluation, the final 8 guidelines were analyzed. The structured table was used to extract the screening subjects, timing, contents, subjects for comprehensive assessment and contents, and summarized contents related to the physical activity and exercise in non-pharmacological approach. As a result, after the completion of cancer treatment, all cancer survivors should be screened regularly using reliable and validated tools. In the case of fatigue, physical activity was recommended as the primary intervention, but it was recommended for other symptoms as adjuvant therapy. Therefore, Cancer survivors should be encouraged to be active in their physical activity, and maintain the moderate intensity physical activity as long as they have no complication related to the cancer treatment. Motivation strategies for physical activity need to be developed and applied.

• Journal of IKEEE
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• v.24 no.3
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• pp.754-765
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• 2020

Currently, Intelligent femoral prostheses that support the corresponding mode in walking and specific movements are being studied. Certain controls such as upstairs, sitting, and standing require a technique to classify control commands based on the user's intention because the mode must be changed before the operation. Therefore, in this paper, we propose a technique that can classify various control commands based on the user's intention in the intelligent thigh prosthesis system. If it is determined that the EMG signal needs to be compensated, the proposed technique compensates the EMG signal using the correlation between the strength and frequency components of the normal EMG signal and the muscle volume estimated by the pressure sensor. Through the experiment, it was confirmed that the user's intention was accurately detected even in the situation where muscle fatigue was accumulated. Improved intention detection techniques allow five control modes to be distinguished based on the number of muscle contractions within a given period of time. The results of the experiment confirmed that 97.5% accuracy was achieved through muscle tone compensation even if the strength of the muscle signal was different from normal due to muscle fatigue after exercise.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.3
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• pp.420-426
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• 2020

In this study, an assistive device for BVM (Bag Valve Mask) was developed. When emergencies occur, rescuers must perform artificial respiration within four minutes utilizing suitable BVM. If not, the patient can suffer serious damage within their brain and body systems. The rescuer must execute artificial respiration until the patient arrives at the hospital. In the process of artificial respiration, the rescuer can feel fatigued in their forearm muscles, particularly those who may have smaller hands or weaker muscle strength. Many products have been developed to solve these problems, but these products are difficult to market and commercialize because of their volume, size, and difficulty of use. In this paper, the BVM assistive device that has been previously manufactured was improved, and an attempt was made to devise a new method that reduces the burden on the user. The BVM assistive device can be divided into three-parts: a head part for compressing the air bag, which can control the amount of air; the body part for coupling with BVM; and finally, the handle that can rotate for better use on various postures of patients. Throughout the experiment, the assistive device could inject an equal amount of air into the patients. As a result, the rescuer could feel less fatigue and inject a suitable amount of air to emergency patients during artificial respiration.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.183-190
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• 1999

The purpose of this study was to develop a portable and convenient closed-loop contrel type electrical stimulator for patients with foot drop. This system restores walking movement as well as prevents from atrophy or necrosis of lower limb muscles and increases blood circulation in hemiplegic patients caused by traffic accident, industrial disaster or stoke. This system detects the changes of the ankle joint angle during walking, and then controls the stimulus intensity automatically to maintain the programmed level of the ankle joint angle. Also, this automatic system controls the stimulus intensity which is affected by increased electrode impedance resulting from long time use. The system detects the joint angle by an optical sensor and includes modified PID control which adjusts the stimulus intensity if the joint angle deviates from the preset value. Stimulus parameters are 30~80 volt, 40 Hz, and 0.2 ms. The system was applied to five hemiplegic patients for 42 days. Duration of stimulation was 15 min/day for the first week and then the duration was gradually increased to 30, 60, 90 and 120 min/day. The muscle force was increased up to 29.7%, muscle fatigue was decreased compared with the level before stimulation and the pattern of locomotion was improved. These results suggest that the electrical stimulator with closed-loop control type is more convenient and effective in restoration of locomotion of patients with foot drop than open-loop system.