• 한국환경보건학회지
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• 제38권4호
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• pp.323-331
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• 2012

Objectives: The objective of this study was to investigate the possible effects of environmental cadmium (Cd) exposure on of bone mineral density (BMD) levels. Methods: A total of 171 residents around abandoned mines in Chungcheongnam-do were surveyed in 2008-2011. Urinary Cd and BMD were analyzed by atomic absorption spectrometry and Dual-Energy X-ray absorptionmetry, respectively. Osteoporosis and osteopenia were defined by T-scores set by the WHO; Tscore ${\geq}$ -1.0, normal; -1.0 > T-score > -2.5, osteopenia; and T-score ${\leq}$ -2.5, osteoporosis. Logistic and multiple linear regressions were applied to estimate the association between U-Cd levels and BMD. Results: The U-Cd geometric mean of 171 Koreans was 2.79 ${\mu}g/g{\cdot}cr$. The U-Cd concentration was significantly higher among women (2.98 ${\mu}g/g{\cdot}cr$) than men (2.39 ${\mu}g/g{\cdot}cr$). With the multiple regression model, the BMD was influenced by U-Cd, BMI, and monthly income. With the logistic regression model, osteoporosis was associated with U-Cd levels (OR = 3.239, 95% CI = 1.770-5.927). Conclusions: We conclude that exposure to cadmium is associated with an increased risk of osteoporosis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권12호
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• pp.6054-6068
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• 2017

In this paper, we defined the relative cross-sectional area of forearm cortical bone and investigated its correlation with hip bone mineral density values of total femur, femoral neck, femoral trochanter, femoral inter-trochanter and femoral ward's triangle, respectively. Based on the correlations, we established a linear transformation between the relative cross-sectional area of forearm cortical bone and each hip bone BMD. We obtained forearm images using CBCT and hip bone BMDs using dual-energy X-ray absorptiometry (DXA) for 28 subjects. We also investigated the optimal forearm region to provide the strongest correlation coefficient. We used the optimized forearm region to establish each linear transformation to estimate BMD values for total femur, femoral neck, femoral trochanter, femoral inter-trochanter and femoral ward's triangle from the relative cross-sectional area of forearm cortical bone, respectively. We observed the strong correlations with total femur (r=0.889), femoral neck (r=0.924), femoral trochanter (r=0.821), femoral inter-trochanter (r=0.867) and femoral ward's triangle (r=0.895), respectively. The strongest correlation was observed in the forearm mid-shaft regions. Our results suggest that the hip bone BMD values can be simply estimated from forearm CBCT images in a convenient sitting position without X-ray exposure on a hip including genital organs, and may be useful for screening osteoporosis.

• 한국식품영양학회지
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• 제20권4호
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• pp.450-459
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• 2007

This study was performed to assess the relationships between bone mineral density(BMD), anthropometric measurements, and maternal factors in postmenopausal women. The anthropometric measurements were taken by a trained practitioner, and the maternal factors of the 85 subjects in Chungnam were acquired by an interview questionaire. The BMDs of the lumbar $spines(L_2-L_4)$, femoral necks(FN), ward's triangles(WT), and trochanters(TR) were measured by dual energy X-ray absorptiometry(DEXA). The BMDs(T-score) for $L_2-L_4$, FN, and WT were 0.996 $g/cm^2$(-1.601), 0.697 $g/cm^2(-1.657)$, and 0.793 $g/cm^2(-1.512)$ respectively, which were assessed as osteopenia by the T-score ; TR was noma1 at 0.718 $g/cm^2(-0.675)$. The 85 subjects in Chungnam were divided into three groups according to their BMD measurements for $L_2-L_4$ and FN, assessed by the T-score. The percentages in the osteoporosis, osteopenia, and normal groups were 32.9%, 42.4, and 24.7%, respectively. The average age was significantly the highest in the osteoporosis group than in the other two osteopenia and normal group(p<0.001). The subjects' BMDs were positively correlated with weight, height, BMI, waist, WHR, OBR and hip circumference, and negatively correlated with the age, duration time after menopause, lactation, the age of last delivery, menarche age, and number of children. The average age at menopause was 48.8. The osteoporosis group's average age at menopause was lower than those of the other groups. However, the BMD of the lumbar spine positively correlated with duration time after menopause and the BMD of the femoral neck with lactation, last delivery, menarch age, number of children. Therefore, researches are needed to find out the effective way to minimize the effect of age and other physiological conditions on the decrease of bone mass density.

• 소음진동
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• 제9권1호
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• pp.196-205
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• 1999

6승의 비선형 항을 가지는 두개의 질량으로 구성된 비선형 해밀톤계에 대해서, 비선형 정규모드인 주기운동의 존재성, 분기현상 및 궤도 안정성을 연구하였다. 운동방정식의 직접적분을 통해 4차원 위상공간에서의 운동궤적을 2차원 면으로 투영하는 푸앙카레 사상을 구하였고, 또한 버크 호프-구스타프슨 표준 변환을 통해 구한 운동적분을 이용하여 에너지가 작을때 푸앙카레 사상에 나타나는 불변 곡선들의 해석적인 표현을 유도하였다. 본 논문에서 연구한 진동계는 비선형 계수의 값에 따라 2개 또는 4개의 비선형 정규모드를 가짐이 밝혀졌다. 푸앙카레 사상은, 분기된 모드는 안정하고, 원래의 모드는 안정한 상태에서 불안정한 상태로 변한다는 것을 분명하게 보여주었다.

• 기본간호학회지
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• 제10권1호
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• pp.30-36
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• 2003

Purpose: The strength of hand grip, low back muscles and knee joint muscles were measured and then compared to the bone mineral density (BMD) of each forearm bones (including ulna and radius), lumbar spine, and femur in young women in order to identify the relationship between muscle strength and bone mineral density. Method: The BMD was measured with a Dual Energy X-ray Absorptiometry and muscle strength was measured with a handgrip dynamometer and a Cybex Norm. Data were analyzed with frequencies, percentages, means, and Pearson correlation coefficients. Result: 1) Higher grip strength correlated positively with higher BMD in the forearm (r=.246, p=.007), higher low back extensor strength with higher BMD in the femur (neck, trochanter and Ward's triangle)($r=.323{\sim}.226$, $p=.003{\sim}.043$) and higher strength in the knee joint extensor with higher BMD in the lumbar spine (r=.227, p=.041), femur neck, and femur trochanter significantly ($r=.295{\sim}.226$, $p=.007{\sim}.043$). There was no significant correlation between the strength of low back extensors and BMD in the lumbar spine, now with strength of knee joint flexor and the BMD in the femur. 2) The muscle strength of each part of the body had significant positive correlations to each other part ($r=.255{\sim}.728$ $p=.021{\sim}.000$) Conclusion: The results of this study showed that with the development of a muscle there was an increased BMD of the corresponding part, and the BMD of each part was influenced by adjacent muscles. To promote the health of bones, it is important to strengthen the muscles of related bones, based on balanced development of all muscles.

• 전기전자학회논문지
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• 제22권3호
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• pp.664-671
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• 2018

일반적으로 감지식 태양광 추적 시스템은 태양의 위치를 추적하기 위해 광센서를 사용하여, 최대 전력을 생산한다. 광센서 채택은 시스템 제작 가격을 상승시키고, 오동작에 의한 성능 저하를 초래할 수 있다. 본 논문에서는 IoT플랫폼 기반의 원격무선 모니터링이 가능하고, 광센서가 없는 새로운 태양광 추적 시스템을 제안한다. 태양광 발전을 위해 사용되는 여러 개의 태양광 패널의 출력 전류량을 비교하여 태양 위치를 광센서 없이 추적한다. 추적 성능의 검증을 위해서 12[V] 20[W] 태양광 발전 시스템을 제작하여 실험을 수행하였다. 본 논문에서 제안한 시스템은 IoT 플랫폼을 사용하여 원격모니터링이 가능하기 때문에 기존 태양광 추적 시스템에 비해 설치, 유지 보수 및 기능 확장의 장점이 있다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권8호
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• pp.4743-4750
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• 2013

Background: Identifying and managing osteoporosis among cancer survivors is an important issue, yet little is known about the bone health of cancer survivors in Korea. This study was designed to measure the prevalence of osteoporosis and to assess related factors among Korean cancer survivors. Materials and Methods: This study was designed as a cross-sectional analysis. Data were obtained from dual energy X-ray absorptiometry measurement of the lumbar vertebrae and femoral neck, and from standardized questionnaires among 556 cancer survivors and 17,623 non-cancer controls who participated in the Fourth and Fifth Korea National Health and Nutrition Examination Surveys (2008-2011). We calculated adjusted proportions of osteoporosis in non-cancer controls vs. cancer survivors, and we performed multivariate logistic regression analysis. Results: The prevalence of osteoporosis among cancer survivors was significant higher than that of the non-cancer controls after adjusting for related factors. Furthermore, osteoporosis among cancer survivors was higher in elderly subjects (60-69 years : adjusted odds ratio (aOR) 3.04, 95% CI : 1.16-8.00, ${\geq}70$ years : aOR 6.60, 95% CI 2.20-19.79), in female cancer survivors (aOR: 7.03, 95% CI: 1.88-26.28), and in a group with lower monthly income (aOR: 3.38, 95% CI: 1.31-8.71). In male cancer survivors, underweight and lower calcium intake were risk factors. Conclusions: These data suggest that the osteoporosis among cancer survivors varies according to non-oncologic and oncologic factors. Effective screening should be applied, and a sufficient and comprehensive management should be matched to individual cancer survivors early after cancer treatment.

• 성인간호학회지
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• 제21권3호
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• pp.303-313
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• 2009

Purpose: The purpose of this study was to investigate bone mineral density(BMD) and identify risk factors of osteoporosis in Korean postmenopausal women. Methods: The subjects consisted of 328 women. The BMD of the calcaneus were measured with peripheral dual energy x-ray absorptiometry. The risk factors were collected by a self-report standardized questionnaire. The differences among the osteoporosis, osteopenia, and normal group were compared by one way analysis of variance test, Scheffe's multiple comparison tests and Logistic regression. Results: The average age was 65 years old and the average T-score was 28.7% with osteoporosis. The Risk factors of osteoporosis were inclined by 24% in age (OR = 1.24, CI = 1.16 ~ 1.31), 53% in menarchal age (OR = 1.53, CI = 1.24 ~ 1.88), 3.5 times in vegetarian (OR = 3.52, CI = 1.66 ~ 7.47), 2 times in small-bowel disease (OR = 2.01, CI= 1.03 ~ 3.94), 5.3 times in arthritis (OR = 5.33, CI = 1.61 ~ 17.67), 5.5 times in eating disorder (OR = 5.50, CI = 1.43 ~ 21.17), 6 times in health perception (OR = 6.08, CI = 2.30 ~ 16.06). The Risk factors of osteoporosis were reduced by 10% in weight (OR = 0.90. CI = 0.83 ~ 0.97), and 10% in menopausal age (OR = 0.90. CI = 0.84 ~ 0.98). Conclusion: The risk factors of osteoporosis were in the general characteristics, menstrual history, history of disease, life style & diet, and health perception. Eating disorder and health perception are highest on the risk factor of osteoporosis in Korean postmenopausal women.

• 보험의학회지
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• 제15권
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• pp.93-98
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• 1996

During the period from January to September 1995, 1.010 Women(premenopausal 466 cases and postmenopausal 544 cases) of employees and family member were observed for bone mineral density of lumbar spine using Dual Energy X-ray Absorptiometry(DEXA) at Medical Department of Korea Life Insurance Co. Ltd. Results obtained were as follows: 1) In premenopausal women 466 cases, the ratio of decreased bone mineral density of lumbar spine according to age groups shows 3rd decade were 5 cases(9.80%) among 51 cases, 4th decade were 31 cases(8.68%) among 357 cases, and 5th decade were 10 cases(17.24%) among 58 cases. 2) In postmenopausal women 544 cases, the ratio of decreased bone mineral density of lumbar spine according to age groups shows 3rd decade were 2 cases(66.67%) among 3 cases, 4th decade were 28 cases(31.11%) among 90 cases, 5th decade were 168 cases(48.70%) among 345 cases, 6th decade were 73 cases(73.0%) among 100 cases, and 7th decade were 4 cases(66.67%) among 6 cases. 3) Bone mineral density begins to decrease with age as early as the 4th decade, even in the premenopausal state. In the 4th decade, premenopausal women exhibit an average 8.68% decrease in bone density. Postmenopausal women in this same age group, however, demonstrate an average bone density decrease of 31.11%.

• Preventive Nutrition and Food Science
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• 제11권4호
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• pp.298-304
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• 2006

This study was carried out to elucidate the relationship among exercise, bone mineral density and antioxidant enzyme activity of postmenopausal women. 60 women residing in the Iksan, Korea area were recruited. The questionnaires were designed to find out exercise habits. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. Parameters of antioxidative capacity, including the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (TA) were analyzed in fasting blood. The mean age, height, weight, and BMI of subjects were 65.0 years, 151.1 cm, 59.5 kg $26.0\;m/kg^2$, respectively. The mean BMDs of subjects were $0.85\;g/cm^2$ (lumbar spine), $0.6\;g/cm^2$ (Femoral neck), $0.49\;g/cm^2$ (trochanter), and $0.40\;g/cm^2$ (Ward's triangle). There was a significant difference in BMD among different age groups (50's, 60's and 70's) showing lower value with increasing age (p<0.05). The mean SOD, GPx, and CAT activities were 138.5 U/mL, 1,273.8 U/mL and 314.3 kU/L respectively, and TA was 1.16 mmol/L. TA of the group which exercised 3$\sim$4 times a week was significantly higher than those of the other exercise groups (p<0.05). The subjects with higher SOD activity also have a higher the T values in the lumbar spine, femoral neck, trochanter, and Ward's triangle. In conclusion, this study revealed that the levels of antioxidant enzyme activity were closely associated with the exercise status and bone mineral density in postmenopausal women.