• Bulletin of the Korean Mathematical Society
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• v.48 no.4
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• pp.791-812
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• 2011

This is a survey on American options. An American option allows its owner the privilege of early exercise, whereas a European option can be exercised only at expiration. Because of this early exercise privilege American option pricing involves an optimal stopping problem; the price of an American option is given as a free boundary value problem associated with a Black-Scholes type partial differential equation. Up until now there is no simple closed-form solution to the problem, but there have been a variety of approaches which contribute to the understanding of the properties of the price and the early exercise boundary. These approaches typically provide numerical or approximate analytic methods to find the price and the boundary. Topics included in this survey are early approaches(trees, finite difference schemes, and quasi-analytic methods), an analytic method of lines and randomization, a homotopy method, analytic approximation of early exercise boundaries, Monte Carlo methods, and relatively recent topics such as model uncertainty, backward stochastic differential equations, and real options. We also provide open problems whose answers are expected to contribute to American option pricing.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.21 no.2
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• pp.15-24
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• 2015

Background: Many people are suffering from neck and shoulder pain due to muscle weakness, muscle fatigue, lack of exercise and accidents during exercise. In this study we compared the effects of McKenzie method and Mulligan technique method. Method: we randomly selected men(10) and women(10) and they are the 20s students of Busan material K college. We divided for McKenzie exercise group and Mulligan exercise group. McKenzie exercise and mulligan exercise applied cervical area three times a week for three weeks. We compared with pre-experiment and after 1~3 week through measuring the electromyography (EMG) change and neck range of motion (ROM). Results: The changes in the EMG at each exercise group, there was a statistically significant difference in each week. Although there was a significant difference after 1 week between the exercise group, the changes in the neck ROM at each exercise group there was no statistically significant difference. Conclusion: After experiment, EMG and neck ROM were increased in McKenzie exercise group and Mulligan exercise group. But Mulligan exercise group showed the change better than McKenzie exercise group in early stage. We suggest the Mulligan exercise method for recovering in early stage of neck ROM.

• Physical Therapy Korea
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• v.8 no.1
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• pp.35-50
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• 2001

The purposes of this study were to investigate the therapeutic effects of an early exercise program after mastectomy and to provide the early exercise program protocol for patients who had undergone mastectomy. The subjects were seventy women who were diagnosed with breast cancer. They were randomly as signed either to a experimental group (n=35) that received early postoperative exercise program or to a control group (n=35) that received only education by nurses. Data were obtained for each patient from goniometric measurements of shoulder flexion, abduction, external rotation, 10 elements of functional performance, and subjective pain evaluation using visual analogue scale (VAS). All variables were measured preoperatively, three days postoperatively, and one month postoperatively. Data were compared by groups using independent t-test and Mann-Whitney U test for parametric or non-parametric data, respectively. There were no significant differences between the groups for all variables preoperatively and at three days postoperatively. But there were significant differences at one month postoperatively. The experimental group showed a statistically significant increases in shoulder flexion, abduction, and external rotation and in the pain VAS at one month postoperatively (p<.05). Also, at one month postoperatively, the experimental group had less difficulty with three elements of functional performance-doing up a 'back' zippered article of clothing, reaching the ipsilateral scapula, and contralateral scapula with the fingers on the operated side-than the control group (p<.05). The results of this study suggest that, after mastectomy, the early exercise program conducted by a well-trained physical therapist can make a significant contribution to the return of more normal shoulder function and activities of daily living and to an increased quality of life.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.15 no.2
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• pp.80-87
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• 2009

Purpose: This study was to determine the effects of a early exercise program on the pain, disability and balance after single-level lumbar discectomy. Methods: Forty patients were randomized into experimental(N=20) and control(N=20) groups. Three days after surgery, patients in the experimental group undertook a 4-week exercise program. Assessments were performed in all patients during the week before surgery and at 4 weeks after. The assessment included measures of back and leg pain(VAS), Oswestry disability index(ODI), stability index(SI) and weight distribution index(WDI). Results: At 4 weeks, VAS, ODI, SI, WDI were significantly reduced in both groups(p<.01). Also the experimental group was significantly reduced back and leg pain(VAS), ODI and WDI were better than the control group(p<.05). Conclusion: It seems that early exercise program is more effective in patients who undergo single-level lumbar discectomy.

• Physical Therapy Korea
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• v.7 no.3
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• pp.1-18
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• 2000

The present study was performed to investigate the prevalence rate of idiopathic scoliosis and to determine the effect of exercise training on scoliotic angle in elementary school children. In this study, two out of five elementary schools in Seosan city were chosen by random sampling. Seven hundred sixty four students (from four grade to the sixth grade student) were selected in two schools. Screening tests were conducted to find idiopathic scoliosis. Among the 764 individuals, 139 subjects who showed positive sign in physical examination took whole spine radiography. Thirty six subjects who had a curve of 10 or greater and consented to participate in the exercise program were selected for the exercise program. The exercise program was performed four times a week for 5 months. The results of this study were as follows: 1) One hundred thirty nine subjects showed positive sign in the scoliosis screening test. 2) The overall prevalence of curve of $10^{\circ}or$ greater in X-ray finding was 8.15%. The prevalencies of curve of $10^{\circ}or$ greater in male and female were 7.1% and 9.2%, respectively. 3) Scoliosis curves were observed at thoracic area (48.4%), at thoracolumbar area (27.4%) and at lumbar area(24.4%). 4) Right side curve was 59.7%, and left side curve was 40.3%. 5) After the 5 month exercise program for scoliosis, the Cobb's angle was significantly decreased. 6) There was no significant difference of Cobb's angle change respect to sex, grades, and scoliosis curve site. Results shown here indicates that an early detection and early exercise for scoliosis can result in decreased the Cobb's angle in elementary school children.

• Journal of the Korean Society of Physical Medicine
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• v.6 no.4
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• pp.455-464
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• 2011

Purpose : This study is to investigate difference in the isometric muscular function of knee joints according to the time of participation in rehabilitation exercise in patients who had anterior cruciate ligament reconstruction. Methods : The subjects of this study were patients by sports injury or accident in the sports rehabilitation center of G hospital. The early exercise program group (n=7) started functional ability exercise from 2 weeks after the surgery and the late exercise program group (n=7) from 6 weeks after the surgery. Statistical analysis was used repeated measure ANOVA to test mean difference by using SPSS 18.0 for windows. Results : First, as to quadriceps femoris muscle according to the time of participation in exercise program, significant difference was observed according to interaction and time. Second, as to hamstring muscle according to the time of participation in exercise program, significant difference was observed in muscle strength according to time. Conclusion : This results suggest that if the effect of exercise program is similar between the early starting group and the late starting group, it is not necessary to have a long period of fixation as in the late exercise program group but is desirable to start functional ability exercise early in order to relieve pains in the knee joints.

• Journal of Korea Association of Health Promotion
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• v.3 no.2
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• pp.189-198
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• 2005

This study examined the applicability of the transtheoretical model(TTM) to understanding exercise behavior of early adulthood. A cross-sectional study was conducted and data wee collected from 1618 adults aged from 20 to 39 through internet survey. Major conclusions wee as follows: 1. Stage distribution for exercise behavior was 15.6%, 26%, 25%, 19%, 14.4% for precentemplation, contemplation, preparation, action, maintenance stages, respectively. 2. Behavioral processes were more frequently utilized than cognitive processes for action and maintenance stage. 3. Self-reevaluation, social liberation and reinforcement were frequently used in precontemplation, contemplation and preparation stages. Self-reevaluation, reinforcement, self-liberation were frequently used in action and maintenance stages. 4. Pros of exercise behavior began to be higher than cons of exercise behavior from the actions stage and continued to increase to maintenance stage. 5. Self-efficacy was higher in action stage than precontemplation, contemplation and preparation stages and the highest in maintenance stage.

• Journal of Korean Clinical Nursing Research
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• v.17 no.1
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• pp.81-89
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• 2011

Purpose: The purpose of this study was to examine the effects of early passive range of motion (ROM) exercise on ROM of lower extremities and foot edema in hemiplegic patients after stroke. Methods: The data were collected between August 2009 and April 2010 from 11 patients in the experimental group and 13 in the control group. The passive ROM exercise was performed twice a day for 2 weeks. Results: In the experimental group, ROM of lower extremities (flexion of hip, flexion of knee and ankle) increased significantly compared to that of the control group. There was no significant difference in foot edema between the two groups. Conclusion: The results indicated that the early passive ROM exercise can improve the ROM of lower extremities, but not the foot edema in patients after stroke.

• Clinical and Experimental Pediatrics
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• v.64 no.5
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• pp.196-207
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• 2021

Over the last few decades, the rates of pediatric obesity have more than doubled regardless of sociodemographic categorization, and despite these rates plateauing in recent years there continues to be an increase in the severity of obesity in children and adolescents. This review will discuss the pediatric obesity mediated cardiovascular disease (CVD) risk factors such as attenuated levels of satiety and energy metabolism hormones, insulin resistance, vascular endothelial dysfunction, and arterial stiffness. Additionally, early intervention to combat pediatric obesity is critical as obesity has been suggested to track into adulthood, and these obese children and adolescents are at an increased risk of early mortality. Current suggested strategies to combat pediatric obesity are modifying diet, limiting sedentary behavior, and increasing physical activity. The effects of exercise intervention on metabolic hormones such as leptin and adiponectin, insulin sensitivity/resistance, and body fat in obese children and adolescents will be discussed along with the exercise modality, intensity, and duration. Specifically, this review will focus on the differential effects of aerobic exercise, resistance training, and combined exercise on the cardiovascular risks in pediatric obesity. This review outlines the evidence that exercise intervention is a beneficial therapeutic strategy to reduce the risk factors for CVD and the ideal exercise prescription to combat pediatric obesity should contain both muscle strengthening and aerobic components with an emphasis on fat mass reduction and long-term adherence.

• Journal of Korean Clinical Nursing Research
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• v.24 no.3
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• pp.283-292
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• 2018

Purpose: This study was conducted to evaluate the effects of early knee joint exercise education program on pain, knee ROM, and satisfaction among patients with a total knee replacement arthroplasty. Methods: An experimental study with non-equivalent groups was conducted using 32 patients for an experimental group and 32 patients for a control group. The experimental group received knee joint exercise education including systemic continuous passive motion (CPM) exercise and knee exercise. The control group received conventional CPM exercise. Pain, flexion and flexion contracture range of motion, and patient satisfaction were evaluated by $x^2$ test, Fisher's exact test, t-test, and repeated measures ANOVA using the SPSS 23.0 Windows program. Results: There were a significant improvement in patients' knee flexion and satisfaction in the experimental group compared to the control group. There was no significant difference in pain and flexion contracture between the two groups. Conclusion: The findings suggest that the proposed education program is efficient and effective when providing nursing care after a total knee replacement arthroplasty.