• Journal of Nutrition and Health
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• v.46 no.2
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• pp.147-155
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• 2013

Higher bone mineral density (BMD) at a young age, calcium intake, and exercise are important for prevention of osteoporosis later in life. We examined familial effects of BMD between mothers and children and adolescents aged 8-19 in Cheonan, Korea and the relationships between BMD and lifestyle parameters, including: food and nutrient intake and exercise. For daughters and sons, significant differences in BMD were observed at the three bone sites (total femur, femur neck, and lumbar spine) according to age, gender, body mass index, exercise, and milk consumption, compared to the reference value for each classification category. Mean differences in children's BMD were observed according to maternal BMD. Energy and calcium intake were lower in both children and mothers in comparison to the estimated daily energy requirement; however, their protein intake was much greater than the daily recommended intake. After adjusting for age and gender and for mother's age, body mass index, and total calorie intake, results of the food frequency test showed an association of a higher intake of meat, meat products, milk and milk products with greater BMD of total femur, femur neck, and lumbar spine of children. In addition, exercise was positively associated with higher BMD. Regression analysis showed a positive association of BMD with age, male gender, exercise, and mother's BMD. In conclusion, after adjustment for environmental parameters, maternal BMD had a positive influence on BMD in daughters and sons. This finding suggests that parents need to check their BMD in order to determine whether their children are at increased risk of low BMD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.995-999
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• 2004

Effects of liquefied calcium supplement on bone mineral density (BMD) and bone health index (osteocalcin, deoxypyridinoline) were investigated in 12 middle aged women. Middle aged women were arranged into 3 groups such as control, Ca500 and Ca750 by liquefied calcium supplement level. BMD was measured at the spine (vertebrae L2-L4). After 6 month, BMD of control group dropped but that of Ca750 were increased from 0.850 to 0.865. The increase in serum calcium and osteocalcin level, and the decrease in urine deoxypyridinoline level were observed in by calcium supplement groups. The bone health index of serum was changed as much as level of calcium supplement. The serum osteocalcin level of Ca750 significantly increased to 7.93 ng/mL after 6 months of calcium supplement. Although we didn't get any significant difference in BMD, we found that the liquefied calcium had no side effect and led effective change in bone health index. Hereafter, we suppose that the liquefied calcium will be available to develop healthy products for preventing osteoporosis.

• The Journal of Korean Obstetrics and Gynecology
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• v.25 no.1
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• pp.93-105
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• 2012

Objectives: This study explored the relationships between Bone Mineral Density (BMD), Body Mass Index(BMI), Age, pain duration outcomes of treatment for Low Back Pain(LBP) in 3 groups(normal,osteopenia,osteoporosis) of female patients. Methods: We evaluated 32 cases of normal, 30 cases of osteopenia and 38 cases of osteoporosis based on BMD, BMI, Age, pain duration among the female inpatients with LBP caused by lumbar disc herniation, admitted at Jaseng Hospital of Oriental Medicine from January 2010 to December 2011. And we measured VNRS(Verbal Numeric Rating Scale) to evaluate the conservative treatment effects. Results: In improvement of female LBP caused by lumbar disc herniation, BMD(T-score), BMI had not proved correlation(P-value>0.05). Female patients' age was negatively correlated with T-score. In pain improvement, BMD normal group showed more reduction of NRS(numeric rating scale) than osteoporosis group, but that had not proved correlation(p-value=0.893). Conclusions: Statically, among the female inpatients with LBP caused by lumbar disc herniation, had no significant differences between the normal group, osteopenia group and osteoporosis group's improvement rate, depending on treating period.

• Progress in Medical Physics
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• v.32 no.3
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• pp.59-69
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• 2021

Purpose: The relationship between computed tomography (CT) number and electron density (ED) has been investigated in previous studies. However, the role of these measures for guiding cancer treatment remains unclear. Methods: The CT number was plotted against ED for different imaging protocols. The CT number was imported into ED tables for the Pinnacle treatment planning system (TPS) and was used to determine the effect on dose calculations. Conversion tables for radiation dose calculations were generated and subsequently monitored using a dosimeter to determine the effect of different CT scanning protocols and treatment sites. These tables were used to retrospectively recalculate the radiation therapy plans for 41 patients after an incorrect scanning protocol was inadvertently used. The gamma index was further used to assess the dose distribution, percentage dose difference (DD), and distance-to-agreement (DTA). Results: For densities <1.1 g/cm³, the standard deviation of the CT number was ±0.6% and the greatest variation was noted for brain protocol conditions. For densities >1.1 g/cm³, the standard deviation of the CT number was ±21.2% and the greatest variation occurred for the tube voltage and head and neck (H&N) protocol conditions. These findings suggest that the factors most affecting the CT number are the tube voltage and treatment site (brain and H&N). Gamma index analyses for the 41 retrospective clinical cases, as well as brain metastases and H&N tumors, showed gamma passing rates >90% and <90% for the passing criterion of 2%/2 and 1%/1 mm, respectively. Conclusions: The CT protocol should be carefully decided for TPS. The correct protocol should be used for the corresponding TPS based on the treatment site because this especially affects the dose distribution for brain metastases and H&N tumor recognition. Such steps could help reduce systematic errors.

• The Journal of Engineering Geology
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• v.34 no.1
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• pp.67-105
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• 2024

This study compares the quartzites of four quartzite units: The Fagfog Quartzite, Dunga Quartzite (member of the Robang Formation), Pandrang Quartzite (member of the Kalitar Formation) and the Chisapani Quartzite. The analysis shows variations in flakiness and elongation, as the Fagfog Quartzite displays low flakiness whereas the Pandrang and the Chisapani have moderate and the Dunga Quartzite has shown variations. The density values of the four quartzite units remain consistent, indicating uniform physical properties and porosity levels. However, bulk density values differ among the quartzites, suggesting variations in particle arrangement, porosity, and density. Regarding strength measures, the Pandrang and the Chisapani Quartzite have higher strength characteristics as compared to the Fagfog and the Dunga Quartzites. The Pandrang Quartzite has the highest average point load strength index, classifying it as "Extremely Strong". The resistance to impact and crushing forces varies among the quartzites, with lower Aggregate Impact Value (AIV) and Aggregate Crushing Value (ACV) indicating higher strength and durability. Durability tests show that the Fagfog Quartzite has high durability against slaking, with a slight decrease observed after the fifth cycle. The Dunga Quartzite shows varying degrees of weathering, while the Pandrang and the Chisapani Quartzite have minimal weight changes, indicating strong resistance to weathering. Magnesium sulfate soundness tests indicate high durability and resistance to degradation for all four units. The Los Angeles abrasion value (LAAV) tests indicate favorable resistance to abrasion for the majority of the Fagfog, Dunga, and the Pandrang Quartzites samples, while Chisapani Quartzite shows more variability in LAAV values. The Pandrang Quartzite shows a higher proportion of elongated particles but lower flakiness index values as compared to Fagfog and Dunga Quartzites while Chisapani Quartzite stands out with a significantly higher presence of flaky particles and lower elongation index values. Mechanically, the Fagfog and Dunga Quartzite show higher strength and better resistance to abrasion and freeze and thaw. The Pandrang Quartzite shows moderate resistance to crushing and sudden effect, while the Chisapani Quartzite has variable resistance to effect. This comparative study emphasizes the diversity and complexity of quartzite rock types, showing the need for comprehensive characterization and assessment to determine their suitability for specific applications.

• Journal of Korean Society of Forest Science
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• v.107 no.2
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• pp.193-204
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• 2018

This study was carried out to select the optimal method of competition index computation according to the competitor selection methods and distant-dependent competition index models, and to analyze the characteristics of competition indices in terms of thinning intensity and tree density targeting Pinus densiflora, Pinus koraiensis, and Larix kaempferi, which are the major coniferous species in Korea. Data was the re-investigated tree information from 240 permanent plots of 80 sites in the stands of P. densiflora, P. koraiensis, and L. kaempferi, which were located in the national forest of Gangwon and North Gyeongsang provinces. The number of subject trees with competition index calculated were 1126 trees for P. densiflora, 4093 trees for P. koraiensis, and 3399 trees for L. kaempferi. For the best competition index computation method, three kinds of competitor selection methods were considered: basal area factor, angle of height, angle of height to crown base. Also, six kinds of competition index models were compared: Lorimer, Martin-EK, Braathe, Heygi, Daniels, and Modified Daniels, which was developed in this study. Correlation coefficient was the best when the competitor selection method of basal area factor $4m^2/ha$ and the competition index model of Modified Daniels were used, and thus, it was selected as the best method for computing competition index. According to the best method by stand characteristics, competition index decreased in all species as thinning intensity was high and tree density was low.

• Journal of Korean Physical Therapy Science
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• v.29 no.2
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• pp.48-56
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• 2022

Background: This study was to identify the effects of blood flow restriction on gluteus muscles thickness, density, and white area index for children with cerebral palsy. Design: Randomized controlled trial. Methods: Twenty children with cerebral palsy were assigned randomly to an experimental (n=10) or control (n=10) group. The experimental group performed a bicycle exercise after blood flow restriction. The control group performed a bicycle exercise. The study used an ultrasonic instrument to measure gluteus muscles thickness, density, and WAI. Wilcoxon signed ranks test was used for determination of differences before and after treatment, and a Mannn-whitney U test was used for determination of differences between treatment groups. Results: As a result of comparison within groups, the experimental and control group showed significant difference for gluteus muscles thickness, density, and WAI after the experiment (p<0.05). In comparison between two groups, the experimental group showed more significant difference in gluteus muscles thickness, density, and WAI than the control group (p<0.05). Conclusion: Based on these results, a bicycle exercise after blood flow restriction effectively improved the gluteus muscles thickness, density, and WAI of children with cerebral palsy.

• Journal of Biomedical Engineering Research
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• v.28 no.6
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• pp.750-755
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• 2007

The linear SEF (Spectral Edge Frequency) parameter and spectrum analysis method can not reflect the non-linear of EEG. This method can not contribute to acquire real time analysis and obtain a high confidence in the clinic due to low discrimination. To solve the problems, the development of a new index is carried out using the bispectrum analyzing the EEG including the non-linear characteristic. At the bispectrum analysis of the 2 dimension, the most significant's power spectrum density peaks appeared much at the specific area in awake and anesthesia state. Because many peaks are showed at the specific area in the frequency coordinate, these points are used to create the new index. Range of the index is 0-100. At the anesthesia, the index is 20-50 and at the awake, the index is 90-60. New index can discriminate the awake and anesthesia state.

• Proceedings of the Korean Society of Medical Physics Conference
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• 1999.11a
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• pp.287-288
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• 1999

• Journal of the Optical Society of Korea
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• v.2 no.2
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• pp.58-63
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• 1998

Cross-talk effects in high-density volume holographic interconnections are investigated using perturbative iteration method of the integral form of Maxwell's wave equation. In this method, the paraxial approximation and negligence of backward scattering introduced in conventional coupled mode theory is not assumed. Interaction geometries consisting of non-coplanar light waves and multiple index gratings are studied. Arbitrary light polarization is considered. Systematic analysis of cross-talk effects due to multiple index gratings is performed in increasing level of diffraction orders corresponding to successive iterations. Some numerical examples are given for first and third order diffraction.