• Journal of Korea Multimedia Society
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• v.21 no.12
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• pp.1407-1416
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• 2018

The purpose of this study was to train a model for the ulna and radius bone segmentation based on Convolutional Neural Networks and to verify the segmentation model. The data consisted of 840 training data, 210 tuning data, and 200 verification data. The learning model for the ulna and radius bone bwas based on U-Net (19 convolutional and 8 maximum pooling) and trained with 8 batch sizes, 0.0001 learning rate, and 200 epochs. As a result, the average sensitivity of the training data was 0.998, the specificity was 0.972, the accuracy was 0.979, and the Dice's similarity coefficient was 0.968. In the validation data, the average sensitivity was 0.961, specificity was 0.978, accuracy was 0.972, and Dice's similarity coefficient was 0.961. The performance of deep convolutional neural network based models for the segmentation was good for ulna and radius bone.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1918-1926
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• 2004

Osteoporosis is defined as a progressive systemic skeletal disorder characterized by low bone mineral density, microarchitectual deteriorations of bone and susceptibility to fracture. numerous methods have been used for quantitative assessment of the skeleton in osteoporosis. QCT has been shown to measure changes in trabecular mineral content in the spine with great sensitivity and precision. To provide the normal reference values and changes of lumbar spinal bone mineral density in korean adult spinal bone mineral density was evaluated in 451 women (229 premenopausal and 222 postmenopausal women) and 206 men, aged 20 to 74 years old in Wonkwang hospital from 2000 to 2004, which was carried out by using QCT. women with oophorectomy, vertebral compression fracture, any history of endocrine disease and use of drugs that alter bone metabolism were excluded. According to the WHO definition, a patient is osteoporotic based on a bone mineral density(BMD) measurement that is 2.5 standard deviations (SDs) below typical peak bone mass of young healthy white women. This measurement of standard deviation from peak mass is called the T score. BMD values of normal women in their 20-24 years, 25-29 years, 30-34 years, 35-39 years, 40-44 years, 45-49 years, 50-54 years, 55-59 years, 60-64 years, 65-69 years, over 70 years were 168.95㎎/㏄ K₂PHO₄, 155.41㎎/㏄ K₂PHO₄, 166.87㎎/㏄ K₂PHO₄, 160.67㎎/㏄ K₂PHO₄, 154.06㎎/㏄ K₂PHO₄, 132.04㎎/㏄ K₂PHO₄, 114.05㎎/㏄ K₂PHO₄, 91.78㎎/㏄ K₂PHO₄, 78.61 ㎎/㏄ K₂PHO₄, 61.35㎎/㏄ K₂PHO₄, 50.53㎎/㏄ K₂PHO₄ Mean bone density of normal women was 115.77K₂PHO₄ K₂PHO₄. BMD values of normal men in their 20-24 years, 25-29 years, 30-34 years, 35-39 years, 40-44 years, 45-49 years, 50-54 years, 55-59 years, 60-64 years, 65-69 years, over 70 years were 171.46㎎/㏄ K₂PHO₄, 162.19㎎/㏄ K₂PHO₄, 155.62㎎/㏄ K₂PHO₄, 147.28㎎/㏄ K₂PHO₄, 137.56㎎/㏄ K₂PHO₄, 137.56㎎/㏄ K₂PHO₄, 101.25㎎/㏄ K₂PHO₄, 109.00㎎/㏄ K₂PHO₄, 103.32㎎/㏄ K₂PHO₄, 91.53㎎/㏄ K₂PHO₄, 88.35㎎/㏄ K₂PHO₄ Mean density of normal men was 115.77㎎/㏄ K₂PHO₄. Peak bone density of women and men was in the age group of 20-24 years and 168.95㎎/㏄ K₂PHO₄, 171.46㎎/㏄ K₂PHO₄, respectively. Bone loss was increased with aging and was accelerated in postmenopausal women than that of premenopausal women. The total loss of BMD for women and men was 70.09% and 48.47%, respectively. Postmenopausal women(mean BMD : 85.83㎎/㏄ K₂PHO₄) had significantly lower BMD than premenopausal women(meand BMD : 144.80㎎/㏄ K₂PHO₄)(p<0.001). The annual loss of BMD of women and men was 2.702㎎/㏄ K₂PHO₄ and 1.795㎎/㏄ K₂PHO₄, respectively. This study provided the BMD reference data for normal korean adult. further studies on BMD in healthy adult and comparison with published data are needed.

• Journal of Periodontal and Implant Science
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• v.25 no.1
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• pp.67-75
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• 1995

The progress of periodontal disease and the wound healing process after treatment result in alveolar bone bone change. So, detection of it is very important in the diagnosis and the radiograph of periodontal disease. Various effects have been made to assess the subtle alveolar bone change and digital subtraction radiography (DSR) has been reported to be the best method in evaluating it qualitatively and quantitatively. The present study was performed to estimate the detectable alveolar bone change qualitatively with digital subtraction radiography. For the in vitro study, 10 intraoral standard radiographs were taken from porcine dry mandible which a rectangular cortical bone chip of 0.1mm to 1.0mm thickness with 0.1mm increment was attached on the buccal surface. The radiographs without and with bone plates were reviewed at the same time by 10 observers and requested to detect the presence of cortical bone plates. Digital Subtraction radiograph was reviewed subsequently by using the DSR system(digital converter-256 grey-levels,DT 2851,Data Translation Co., U.S.A;IBM 386 ; CCD camera, FOTOVIX, Tamrom Co., Japan). The detectable thickness of cortical bone plate was O.4mm on the intraoral radiograph and 0.2mm on the subtaction images. For the human study, radiographs were taken from patients by using intraoral film holding device and aluminum reference wedge before and 3 month after bone graft and 1 week after osteoplasty. The grey level change was estimated in the subtraction images and calculated to aluminum equivalent thickness. The grey level of the grafted site was higher that that of healthy controls. Average grey levels of change on healthy controls were O.48mm aluminum equivalent. However, the amount of changes in grafted sites were 1.87mm aluminum thickness equivalent and in the site of osteoplasty were -1.49mm aluminum thickness equivalent. In conclusion, digital subtraction radiography was more effective in detecting as subtle change of alveolar bone than intraoral standard radiography. With the aid of quantitative analysis of digital subtraction radiography, alveolar bone resorption of apposition can be estimated during diagnosis and treatment of periodontally diseased patients.

• Archives of Plastic Surgery
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• v.32 no.4
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• pp.467-473
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• 2005

Calvarial bone grafting in craniomaxillofacial trauma and facial reconstructive surgery is now widely recognized and accepted as a standard procedure. One of the commonly reported problems of calvarial bone graft is the contour defect caused by partial resorption of the graft. But, there are few reports that discuss the fate of the calvarial bone graft based on the quantitative data. In this article, the changes of grafted calvarial bone were evaluated using 3-dimensional computed tomography(CT). 9 patients were observed with the CT scans at 2mm thickness immediately after operation and at the time of last follow-up. The area of the bone defect was segmented on the 3-dimensional CT image and calculated by AnalyzeDirect 5.0 software. The immediate postoperative bone defect area of the recipient site and the donor site were $612.9mm^2$ and $441.5mm^2$, respectively, which became $1028.1mm^2$ and $268.8mm^2$, respectively at the last follow-up. In conclusion, the bone defect area was less increased on the donor site of calvarial bone graft than on the recipient site. And the CT scan is a valuable imaging method to assess and follow-up the clinical outcome of calvarial bone grafting.

• Korean Journal of Community Nutrition
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• v.3 no.3
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• pp.380-388
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• 1998

This study was conducted to investigate the distribution of bone density according to age and the prevalence rate of osteoporosis I 613, middle-aged women who visited Saint Bundo Hospital in Pusan from June to December, 1997. Mean bone density of lumbar spine(L2L4), and femoral neck of 50-59 years of age was significantly lower than those of 40-49 years of age(p<0.05). At the 60years of age, mean bone density of two sites were less than those of 50-59 years of age. Mean bone density of lumbar spine tin the group of sixties were 20.7% lower than that of group aged under 40 ; For femoral neck, women in their sixties showed 22.6% lower density compared to the women aged under forty. Bone density of ward's triangle of sixties were the least, which was 34.2% lower than that of group aged under 40. Bone density in lumbar spine, femoral neck, trochanter and ward's triangle correlates strongly with each other(p<0.001). The proportion of osteoporosis was 3.6% in the group of forties, 10.9% in the group of fifties and 33.8% for the group aged over 60, which was assessed by bone density of lumbar spine. Bone density of lumbar spine, femoral neck and ward's triangle were positively correlated with height, weight and BMI(p<0.001∼p<0.01), and weight showed highest correlation with the bone density. Forty-four percent of variation in lumbar spine bone density was explained by age and weight.

• Journal of the Korean Society of Physical Medicine
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• v.14 no.3
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• pp.134-141
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• 2019

PURPOSE: This study conducted aA forward-looking study of elite water polo athletes, who trained at National Training Center, was conducted to determine the correlation between the incidence of sports injuries and the bone density among national water polo players. METHODS: Data on the general characteristics of all study subjects were analyszed usingin descriptive statistics. The incidence of sports injuries was calculated from the incidence of sports injuries per 1,000 hours and the incidence of sports injuries resulting from exposure to 1,000 training sessions. The incidence of all sports injuries was calculated with a 95% confidence interval. Furthermore, Pearson's correlation was calculated conducted to determine the correlation between sports injuries and bone density, bone mass and body composition. RESULTS: Water polo athletes suffered a total of 127 sports injuries in the three-year period, while the athletes suffered 3.5 sports injuries each year. The Ooverall injury rate of 3.2(95% CI 2.68-3.81) per 1,000h, 18.0(15% CI 14.89-21.16) of sports injuries per 1,000AE. For all athletes, 50.4% of the injuries were classified as mild, followed by moderate (26.8%) and severe (22.8%). The lower the bone density in all areas of sports injuries, the higher the incidence of sports injuries. In addition, and the lower the bone mass in all areas except for light injuries, the higher the incidence of sports injuries. CONCLUSION: In tThe correlation between sports injuries and bone density and bone composition of water polo athletes, revealed a significant correlation between the bone density and bone mass were statistically significant, and the lower the bone density and bone mass, the higher the incidence of sports injuries.

• 대한근관절건강학회:학술대회논문집
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• 1996.04a
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• pp.110-121
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• 1996

It is well defined that osteoporosis is an age related disorder and associated with decreased bone mass. It is one of the most important disease lacing the aging population because of its association with fracture of the hip, vertebrae and distal radius. The disease provoke a significant economic burden and major public health problem of an elderly. The life-time risk of hip fracture in white women is approximately 15% which is equal to the combined risk of breast, uterine, and ovarian cancer. Despite its deleterious effect on women's health, knowledge of the epidemiology of osteoporosis in Korea is only beginning. 1970 in Korea has non as the crossover period between the chronic and an Infectious diseases. As the result, the infant mortality declined and an elderly population in Korea increased significantly in the past decade, The average life expectancy of women in Korea is now about 75 years. Thus, the majority of Korean women will spend approximately one-third of their life in the postmenopause state. Therefore, better understanding of bone metabolism and fracture incidence in Korean population is a great interest for the medical community as well as for public health. Currently, no population based epidemiologic data are available to support the incidence of osteoporotic fractures in Korea. However, available data suggest that significant declining of bone mineral density (BMD [g/$cm^2$]) has been occurring in Korean women after menopause. In same population, peak BMD was observed around 33-39 years of age and continue to decline thereafter. An accelerated bone losses occur after the menopause and the average loss is approximately 13% within 15 years from the menopause. The incidence of fracture was highly correlated with an age and bone mineral density. The mean age of menopause in Korean women was 47 years and this age appears to getting younger when analyzed by the birth cohort. An earlier menopausal age and increase life expectancy place Korean women at increase risk for osteoporosis and bone fracture. Korean or Asian women are no longer protected from the risk of bone fracture. Therefore, an early prevention or intervention schemes are essential before the outbreak of osteoporosis and/or fracture occurs in Korean or Asian women.

• Research in Community and Public Health Nursing
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• v.24 no.2
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• pp.236-244
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• 2013

Purpose: This study was to investigate lifestyles and identify factors influencing the bone mineral density (BMD) among employees in a community. Methods: Data were collected from 199 employees. Their lifestyles and BMIs were measured with a self-report questionnaire. As for their BMDs, their calcanei were measured with Quantitative Ultrasound. Results: Assessing their BMDs with reference to the WHO standards, 52.8% of the subjects' calcaneus BMDs were normal and 44.2% showed osteopenis, 3.0% showed osteoporosis. Age (odds ratio=1.05, p=.029), exercise (odds ratio=.31, p=.006) and the number of eating meals per day (odds ratio=1.97, p=.046) were significant factors influencing the subjects' BMDs. Conclusion: Strategies to emphasize exercise and dietary habits in employees are important for improving their bone mineral density. Programs for improving bone mineral density based on life cycle need to be developed.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.182-191
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• 2005

It is very important to obtain a high quality of bone image for an accurate ultrasonic measurement of bone mineral density. In this study, we suggested a technique to acquire an optimal image by adapting an acoustic lens and a properly selected ultrasonic probe. Also, we have applied an image processing algorithm with which automatically makes a decision of brightness and contrast of image by generating threshold level, a composition of ultrasonic data, an elimination of noise using modified median filter, and a real time interpolation. We could confirm much improved resolution of bone image with acoustic lens attached to the ultrasonic probe and with the image processing algorithm suggested in this study. Therefore, it became possible to precisely diagnose the osteoprosis using ultrasonic imaging technique.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.527-528
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• 2006

In the proposed research plan, the effects of anisotropic and time-dependent mechanical properties on nanoindentation measurements of osteonic lamellae in a human cortical bone are investigated. The most popular method(Oliver-Pharr method) in nanoindentation data analysis is based on the assumption of elastic isotropy. Since cortical bone has exhibited anisotropy, it is necessary to consider the effects of anisotropy on nanoindentation measurement for cortical bone. By comparison with the contact area obtained from monitoring the contact profile in FEA simulations, the Oliver-Pharr method was found to underpredict or overpredict the contact area due to effects of anisotropy. The mount of error depended on the indentation orientation. The indentation modulus results and were also similar to moduli calculated from mathematical model. The Oliver-Pharr method has been shown to be useful for providing first order approximations in analysis of anisotropic mechanical properties of cortical bone, although the indentation modulus is influenced by anisotropy.