• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.1
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• pp.1-10
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• 2017

The difficulties in opening and closing a sport utility vehicle (SUV) tailgate is important aspect of JD (James David) power's Initial Quality Survey (IQS) assessment, and affective quality has a big impact on the the success of thesedays products. The purpose of this study is to evaluate the perceived difficulty and satisfaction of customers by the opening and closing of the tailgate and to grasp the relationship between them and the opening and closing reaction force. The mechanical force required to open and close 42 domestic and overseas SUV tailgates was measured with the help of an auto company. In the experiment, 100 male drivers in their 20s to 50s evaluated perceived difficulty and satisfaction with opening and closing the tailgate. The results of the analysis showed that perceived difficulty and satisfaction were statistically different depending on the vehicle, but did not depend on the personal characteristics of the participants. The perceived difficulty and satisfaction regression model of tailgate opening and closing was developed by mechanical force variables and had a relatively high adjusted $R^2$ ranging from 0.62 to 0.73. The models showed that the the initial close and open force, the difference between initial and maximum close force and the difference between initial and auto-fall angle should be small for the low perceived exertion and high satisfaction. In addition, the correlation analysis between IQS score of tailages and perceived difficulty and satisfaction showed that the IQS scores were more related to the perceived difficulty and satisfaction of closing than those of opening. The results of the study will be helpful to design and test mechanical open and close structure of SUV tailgates.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.15 no.1
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• pp.61-70
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• 2005

This study investigated the spinal loads(L5/S1 disc compression and shear forces) predicted from four biomechanical models: one EMG model and three optimization models. Three objective functions used in the optimization models were to miminize 1) the cubed muscle forces : MF3, 2) the cubed muscle stress : MS3, 3) maximum muscle intensity : MI. Twelve healthy male subjects participated in the isometric voluntary exertion tests to six directions : flexion/extension, left/right lateral bending, clockwise/ counterclockwise twist. EMG signals were measured from ten trunk muscles and spinal loads were assessed at 10, 20, 30, 40, 50, 60, 70, 80, 90%MVE(maximum voluntary exertion) in each direction. Three optimization models predicted lower L5/S1 disc compression forces than the EMG model, on average, by 31%(MF3), 27%(MS3), 8%(MI). Especially, in twist and extension, the differences were relatively large. Anterior-posterior shear forces predicted from optimization models were lower, on average, by 27%(MF3), 21%(MS3), 9%(MI) than by the EMG model, especially in flexion(MF3 : 45%, MS3 : 40%, MI : 35%). Lateral shear forces were predicted far less than anterior-posterior shear forces(total average = 124 N), and the optimization models predicted larger values than the EMG model on average. These results indicated that the optimization models could underestimate compression forces during twisting and extension, and anterior-posterior shear forces during flexion. Thus, future research should address the antagonistic coactivation, one major reason of the difference between optimization models and the EMG model, in the optimization models.

• Journal of Families and Better Life
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• v.23 no.6 s.78
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• pp.79-93
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• 2005

The study investigated whether the characteristics of human figures in Kinetic Family Drawing showed significant differences according to the drawer's personality (neurosis, intellectual openness, friendliness, extroversion, sincerity). The participants of this study were 340 high-school girls. The Five Factors Personality Test was conducted to assess personality factors and the Kinetic Family Drawing Test was used to obtain data on drawing characteristics. The data were analyzed using Chi-square. The results of this study are as follows: First, there were significant differences in ten subcategories such as face, countenance, eyes, mouth, inclusion of body. hands, posture, erasure, exertion of pressure on the paper, and lines, according to the degree of neurosis. Second, there were significant differences in countenance, eyes, posture, exertion of pressure on the paper, and lines according to the degree of extroversion. Third, there were significant differences in face, countenance, eyes, and posture, according to the degree of openness. Fourth, there were significant differences in erasure and lines according to the degree of friendliness Fifth, there were significant differences in countenance and posture according to the degree of sincerity. This study proved that among the personality factors, neurosis is most highly related with characteristics of persons drawn in the Kinetic Family I)lawing, whereas countenance and posture in the drawing were highly indicative of personality factors.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.124-128
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• 2009

Pulmonary arteriovenous malformations (PAVMs) are direct communications between pulmonary arteries and pulmonary veins, resulting in right-to-left shunts that may cause cyanosis, dyspnea, and digital clubbing. Neurological complications such as intracerebral hemorrhage or brain abscess may result from cerebral thrombosis or emboli. In most cases, they remain unrecognized until the late teenage years. Here, we report a case of a 6-year-old boy who presented with perioral cyanosis, digital clubbing, and dyspnea on exertion. A plain chest X-ray showed a focal nodular opacity in the right lower lobe (RLL), and a diagnosis of a large PAVM in the RLL was confirmed by chest computed tomography. A right lower lobectomy was successfully performed without any complications. Although their incidence in children is low, PAVMs should be suspected as a possible cause of cyanosis and dyspnea of non-cardiac origin, and should be treated promptly to prevent further neurological complications.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.205-207
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• 2008

Purpose: Although muscle hernia has been well described in the lower-extremity, muscle hernias in the upper extremity are extremely rare. As with lower extremity muscle hernias, the forearm muscle hernia may result from forced exertion of strenuous activity or following blunt trauma. The objective of this paper is to report an extraordinary case of forearm muscle hernia after radial forearm sensory tendocutaneous free flap with references. Methods: A 58-year-old male patient received wide excision and radical neck dissection and lower lip reconstruction with radial forearm sensory tendocutaneous free flap for squamous cell cancer on the lower lip. 16 weeks after the operation, he complained of protruding mass on the forearm and the size was increasing. In postoperative 18 weeks, MRI showed herniation of flexor digitorum superficialis. For unaesthetic cause and preventing progress, the authors performed direct fascial closure and Mesh graft. Results: In 12 months after the surgery there was no recurrence and the patient remained symptom-free. Conclusion: Pain on extremity exertion and unaesthetic buldge of forearm due to forearm muscle hernia were the primary indications for surgery which consist of direct closure, fasciotomy, fascia lata onlay graft, fascia lata inlay graft, etc. The authors experienced uncommon forearm muscle hernia after radial forearm free flap and satisfying result of treatment.

• Childhood Kidney Diseases
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• v.22 no.2
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• pp.52-57
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• 2018

Purpose: Rhabdomyolysis is a metabolic disorder in which the content of damaged muscle cells is released into plasma. Its manifestations include asymptomatic, myalgia, gross hematuria, and complications of acute kidney injury. Because of limited data on rhabdomyolysis in children, we performed this study to determine clinical characteristics of rhabdomyolysis in children. Methods: We retrospectively reviewed the records of patients with rhabdomyolysis who were treated at the Pusan National University Children's hospital from January 2011 to July 2016. The diagnostic criteria were serum myoglobin level of ${\geq}80ng/mL$, exclusive of acute myocardial injury, cardiac arrest, and brain damage. Results: Forty-five patients were enrolled; mean age, $116{\pm}68$ months. Of these, 35 were boys and 10 were girls. Twenty-six patients experienced myalgia and 12 patients showed gross hematuria. Among these, seven patients initially had both myalgia and gross hematuria. The most common causes of rhabdomyolysis were infection, physical exertion, prolonged seizures, metabolic abnormalities, and drug addiction. Acute kidney injury (AKI) was the most common complication, followed by disseminated intravascular coagulation. Thirty-seven patients improved with sufficient fluid supply but two patients underwent hemodialysis due to deterioration of kidney function. Gross hematuria, positive occult blood test, and positive urine protein were more common in patients with AKI than in those without AKI. Conclusions: In children, infection was the most common cause of rhabdomyolysis. Most patients recovered by sufficient fluid therapy. However, in severe cases, especially in patients with underlying kidney disease, hemodialysis may be necessary in the present study.

• Physical Therapy Rehabilitation Science
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• v.7 no.1
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• pp.18-22
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• 2018

Objective: This study aimed to investigate the effect of different-sized airways of the inspiratory muscle trainer (IMT) on maximal inspiratory pressure (MIP) and the rating of perceived exertion, as measured by the modified Borg scale (m-Borg). Design: Cross-sectional study. Methods: Twenty healthy subjects (10 men, 10 women) volunteered for the study. The spirometry was used to measure MIP. The trial order of the three spirometry conditions was chosen randomly. After measuring the MIP and before taking the final break, each of the conditions were immediately measured using the m-Borg. All subjects used the IMT with an airway diameter of 5-, 6-, and 7-mm. Results: The MIP significantly decreased with the decreasing airway diameter of the IMT (p<0.001), and the differences in all three conditions (7- and 6-mm, 6- and 5-mm, and 7- and 5-mm airways) were significant (p<0.05). The RPE significantly increased with the decreasing airway diameter of the IMT (p<0.001), and the differences in all three conditions (7- and 6-mm, 6- and 5-mm, and 7- and 5-mm airways) were significant (p<0.05). Conclusions: Decreasing the airway diameter of the IMT decreased the MIP and increased the m-Borg. In regards to physical exercise within the clinical setting, the m-Borg could be a useful as a prior monitoring method to prevent dyspnea for patients with narrowed airways (blocked with secretion or sputum in pulmonary disease) and the different-sized airways of the IMT could be applied as a useful tool to improve MIP for prevention of pulmonary disease.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.4
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• pp.1-8
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• 2018

Whole body fatigue detection is an important phenomenon and the factors contributing to whole body fatigue can be controlled if a mathematical model is available for its assessment. This research study aims at developing a model that categorizes whole body exertion into fatigued and non-fatigued states based on physiological and perceived variables. For this purpose, logistic regression was used to categorize the fatigued and non-fatigued subject as dichotomous variable. Normalized mean power frequency of eight muscles from 25 subjects was taken as physiological variable along with the heart rate while Borg scale ratings were taken as perceived variables. The logit function was used to develop the logistic regression model. The coefficients of all the variables were found and significance level was checked. The detection accuracy of the model for fatigued and non-fatigues subjects was 83% and 95% respectively. It was observed that the mean power frequency of anterior deltoid and the Borg scale ratings of upper and lower extremities were significant in predicting the whole body fatigued when evaluated dichotomously (p < 0.05). The findings can help in better understanding of the importance of combined physiological and perceived exertion in designing the rest breaks for workers involved in squat lifting tasks in industrial as well as health sectors.

• Korean Journal of Exercise Nutrition
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• v.25 no.3
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• pp.8-15
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• 2021

[Purpose] Excessive reactive oxygen species (ROS) induced by prolonged high-intensity exercise can cause structural and functional damage. Antioxidant polyphenol supplementation, which reduces ROS levels, may improve high-intensity exercise performance. We evaluated the effect of lychee fruit extract, which contains high levels of low-molecular-weight oligomerized polyphenols, on high-intensity exercise performance. [Methods] Ten male athletes were included in an open-label trial that consisted of control and intervention phases, with a 7-day washout period between phases. The participants were administered oligomerized lychee fruit extract for seven days, whereas no intervention was given in the control phase. High-intensity intermittent exercise and the Wingate test were performed. The power output, blood lactate levels, reactive oxygen metabolite levels, biological antioxidant potential, heart rate, and rate of perceived exertion were measured. [Results] The average power output was significantly higher in the intervention phase than in the control phase (P < 0.01), while the change in blood lactate levels was significantly lower in the intervention phase than in the control phase (P < 0.05). The average heart rate was significantly higher in the intervention phase than in the control phase (P < 0.05), without changing the rate of perceived exertion. Although there was no difference in reactive oxygen metabolite levels between the phase, the change in biological antioxidant potential was larger in the intervention phase than in the control phase (P = 0.06). The Wingate test showed no significant differences between the phase. [Conclusion] Short-term loading with oligomerized lychee fruit extract may increase performance during high-intensity intermittent exercise by improving metabolism.

• Journal of Life Science
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• v.18 no.9
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• pp.1263-1270
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• 2008

The purpose of this study is to investigate the effect of exercise mode and anti-hypertensive drug responding status on the cardiovascular response and perceived exertion in acute coronary syndrome (ACS) patients. Seventy-five patients who participated in six-week exercise rehabilitation therapy performed a treadmill running and a cycle ergometer exercise at intensities of 60%HRR and 85%HRR respectively. Systolic and diastolic blood pressure, mean arterial blood pressure (MAP), rate pressure production (RPP), and ratings of perceived exertion (RPE) were measured. The results of cardiovascular response by the different exercise modes with moderate and intensive intensity of anti-hypertensive drug responder and nonresponder ACS patients were following: First cycle ergometer exercise induced significantly higher SBP, DBP, MAP, RPP and MAP than treadmill running exercise at the intensities of 60%HRR and 85%HRR in both anti-hypertensive responder and nonresponder ACS patients (p<0.05). Secondly anti-hypertensive nonresponder ACS patients had significantly higher DBP and MAP that anti-hypertensive responder ACS patients at all the exercise modes (p<0.05). Finally there was no difference of RPP between anti-hypertensive responder and nomresponder ACS patients, although anti-hypertensive nonresponder ACS patients showed higher blood pressure and RPP than anti-hypertensive responder ACS patients. In conclusion, cycle ergometer induced increased cardiovascular response at same intensities of treadmill running exercise and anti-hypertensive nonresponder ACS patients had even more increased cardiovascular response than anti-hypertensive responder ACS patients with no difference in perceived exertion during exercise. These results suggested that cycle ergometer exercise should be greatly careful with the risk of higher blood pressure, especially for those who are patients with hypertensive blood pressure.