• Journal of the Korean Society of Manufacturing Process Engineers
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• v.17 no.5
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• pp.45-51
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• 2018

Roll forming refers to the production of long plate-molded products, such as panels, pipes, tubes, channels, and frames, by continuously causing the bending deformation to thin plates using rotating rolls. As the roll forming method has advantages in terms of mass production because of its excellent productivity, the size of the roll forming industry has been continuously increasing and the roll forming method is increasingly being used in diverse industrial fields as a very important processing method. Furthermore, as the roll forming method mainly depends on the continuous bending deformation of the plate materials, the time and the cost of the heterogeneous materials developed in the process are relatively large when considered from the viewpoint of plastic working because many processes are continuously implemented. The existing studies on roll forming manufacturing have reported the loss of large amounts of time and materials when the raw materials or product types were changed; further, they have stated that the use of this method can hardly guarantee the uniformity of the formed shapes and the consistency in terms of size and cannot detect all the defects occurring during the mass production and related to the dimensions. Therefore, in this research, a real-time process data-based smart roll forming method that can be applied to multiple products was studied. As a result, a roll forming system was implemented that remembers and automatically sets the changes in the finely adjusted values of the supplied quantities of individual heterogeneous materials so that the equipment setting changing time for heterogeneous material replacements or changes in the products being produced can be shortened. It also secures the uniformity of the products so that more competitive and precise slide-rail products can be mass-produced with improvements in the quality, price, and productivity of the products.

• Journal of Korean Medicine for Obesity Research
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• v.24 no.1
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• pp.54-67
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• 2024

Objectives: The purpose of this study was to evaluate changes in body weight and blood pressure and also analyze adverse events after weight loss program using Gamitaeeumjowee-tang in patients with class II or III obesity, considering for metabolic and bariatric surgery. Methods: A retrospective chart review was conducted on class III obesity or class II obesity patients with comorbidities, who participated in 24-week weight loss program using Gamitaeeumjowee-tang (n=54). The analysis included changes in body weight, body mass index, fat mass, skeletal muscle mass, waist-hip ratio and blood pressure before and after the program. And also calculated the proportion of patients who lost more than 5%, 10%, and 15% of their initial weight. Adverse events were assessed by causality, severity and system-organ classes. Results: After the weight loss program, body weight decreased 12.21±6.43 kg (12.77%), and BMI decreased 4.61±2.25 kg/m² (12.75%) on average (P<0.05). The 90.7% of the subjects lost more than 5% of their weight, 68.5% lost more than 10%, and 35.1% lost more than 15% of their weight. Blood pressure significantly decreased 11.04±14.53 mmHg in systolic and 7.28±11.89 mmHg in diastolic on average (P<0.05). The 97% of adverse events were mild, and 75% were evaluated as 'unlikely' in the causality evaluation. Conclusions: The results of this study, the weight loss program using Gamitaeeumjowee-tang showed significant weight loss and blood pressure reduction in patients with class III obesity or class II obesity with comorbidities, without serious adverse events. Well-designed clinical studies are recommended for the future.

• The Korean Journal of Ecology
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• v.17 no.3
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• pp.311-318
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• 1994

We examined spatial and temporal patterns of root decomposition for three and half years, from October 1986 to April 1990, in semi-arid Chihuahuan Desert. Decomposition of roots occurred in a two-phased pattern: an early period of rapid mass loss followed by a period of slower loss. The rate of root decomposition had a high negative correlation with the initial lignin concentration in roots (r=-0.84, p<0.05). Annual mass loss rate of Baileya multiradiata, a herbaceous annual, was the highest with the value of 0.60, while that of Panicum obtusum. a perennial grass which was restricted to playa, was the lowest with 0.13. The mass loss rate of roots in the playa was the lowest among the vegetation zones along the transect. After 42 months elapsed, fluffgrass roots in playa lost 40% of the initial mass, while in other sites it lost on average 55% of the initial mass. In all roots except for desert marigold, there was an initial release of nitrogen early in decomposition followed by net nitrogen immobilization. Nitrogen concentration of the desert marigold roots showed linear increase from the beginning. Lignin concentration of perennial grass roots were higher than those of herbaceous annual and woody perennial root.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.535-544
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• 2012

Filtration on horizontal filter medium facing upward is accompanied by sedimentation. When sedimentation phenomenon is not considered, the average specific cake resistance by filtration could be in error more than two times. In the previous paper on this subject, it was insisted that the solid mass fraction of suspension changes in filtration period by sedimentation. But we could not find out the degree of change. At the first half of this paper, the average specific cake resistance measured by permeation will be proved to be exact in several means. The average specific cake resistance conventionally measured by filtration does not give correct results because it uses initial solid mass fraction of suspension. Then we calculated the changed solid mass fraction of suspension due to sedimentation during filtration by the experimental values obtained "filtration-permeation" method. We also determined the solid mass fraction at a certain moment of filtration from the suspension height and a new equation derived in this study. The two results were compared and proven that they almost matched.

• Structural Engineering and Mechanics
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• v.40 no.5
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• pp.637-654
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• 2011

The present paper studies the variation of the natural frequencies and mode shapes of rectangular plates carrying a three degree-of-freedom spring-mass system (subsystem), when the subsystem changes (stiffness, mass, moment of inertia, location). An analytical approach based on Lagrange multipliers as well as a finite element formulation are employed and compared. Numerically reliable results are presented for the first time, illustrating the convenience of using the present analytical method which requires only the solution of a linear eigenvalue problem. Results obtained through the variation of the mass, stiffness and moment of inertia of the 3-DOF system can be understood under the effective mass concept or Rayleigh's statement. The analysis of frequency values of the whole system, when the 3-DOF system approaches or moves away from the center, shows that the variations depend on each particular mode of vibration. When the 3-DOF system is placed in the center of the plate, "new" modes are found to be a combination of the subsystem's modes (two rotations, traslation) and the bare plate's modes that possess the same symmetry. This situation no longer exists as the 3-DOF system moves away from the center of the plate, since different bare plate's modes enable distinct motions of the 3-DOF system contributing differently to the "new' modes as its location is modified. Also the natural frequencies of the compound system are nearly uncoupled have been calculated by means of a first order eigenvalue perturbation analysis.

• Journal of Korean Medicine for Obesity Research
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• v.5 no.1
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• pp.47-56
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• 2005

Objectives : This study was performed to investigate the change of bone mineral density(BMD) after 1 month Kirindiet therapy including very low calory diet(VLCD) in middle-aged obese women$(65>age{\geqq}40,\;BMI{\geqq}25)$ under normal $BMD(T-score{\leqq}0)$. Methods : We examined body weight, body fat, protein mass and BMD of 13 middle-aged obese women who visited to Kirin Oriental Hospital from Sep. 7. 2004 to Oct. 12. 2005 before and after 1 month Kirindiet therapy. Body weight, body fat and protein mass was checked by Inbody 4.0 and BMD was checked by quantitated computed tomography. Wilcoxon signed rank test was used for analyzing changes of body weight, body fat, protein mass and BMD before and after treatment. Results : Alter 1 month treatment body weight(-4.89Kg, -6.74%, p=0.001), body fat(-3.47Kg, p=0.001) and protein mass(-0.97Kg, p=0.006) was significantly reduced. BMD was significantly increased in all cases(+4.87mg/cc, +4.16%, p=0.001). Though body weight, body fat and protein mass were significantly reduced, BMD was significantly increased(p<0.01). Conclusions : In this study, we can conclude that after 1 month Kirindiet therapy including VLCD, BMD in middle-aged obese women under normal BMD was significantly increased inspite of reduction of body weight, body fat and protein mass.

• Nutrition Research and Practice
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• v.12 no.3
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• pp.222-232
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• 2018

BACKGROUND/OBJECTIVES: Since gain or loss of skeletal muscle mass is a gradual event and occurs due to a combination of lifestyle factors, assessment of dietary factors related to skeletal muscle is complicated. The aim of this study was to investigate the changes in total energy intake according to the level of skeletal muscle mass. SUBJECTS/METHODS: A total of 8,165 subjects ${\geq}30years$ of age from the Korean National Health and Nutrition Examination Surveys (KNHANES) 2008-2011 were included in the analysis, and multivariate-adjusted regression analyses were performed to analyze the association of the quartiles of sarcopenia index (SI) with energy intake of the study population after adjusting for age and metabolic parameters. RESULTS: The increase in SI quartile was in proportion to the gradual decrease in systemic lipids and the anthropometric measurement of fat accumulation (P < 0.001). Subjects in higher SI quartiles tended to consume more total energy and energy-producing nutrients than those in lower quartiles (P < 0.001). After age, body weight, alcohol consumption, and metabolic parameters were adjusted in the analysis, total energy intake gradually increased according to the increase in SI quartile, and the association between total energy intake and SI was more pronounced in men. However, the risk (odd ratio) of having a low SI was not affected by any single macronutrient intake. CONCLUSION: In this study, total energy intake was positively associated with SI and relative skeletal mass in both men and women. However, no significant association or a weak association was observed between any single macronutrient intake and skeletal muscle mass. The data indicated that acquiring more energy intake within the normal range of energy consumption may help to maintain skeletal muscle mass.

• Nuclear Engineering and Technology
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• v.49 no.3
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• pp.645-650
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• 2017

This technical note demonstrates the feasibility of using laser ablation inductively coupled plasma mass spectrometry for the characterization of U-7Mo/Ale5Si dispersion fuel. Our measurements show 5.0% Relative Standard Deviation (RSD) for the reproducibility of measured $^{98}Mo/^{238}U$ ratios in fuel particles from spot analysis, and 3.4% RSD for $^{98}Mo/^{238}U$ ratios in a NIST-SRM 612 glass standard. Line scanning allows for the distinction of U-7Mo fuel particles from the Al-5Si matrix. Each mass spectrum peak indicates the presence of U-7Mo fuel particles, and the time width of each peak corresponds to the size of that fuel particle. The size of the fuel particles is estimated from the time width of the mass spectrum peak for $^{98}Mo$ by considering the scan rate used during the line scan. This preliminary application clearly demonstrates that laser ablation inductively coupled plasma mass spectrometry can directly identify isotope ratios and sizes of the fuel particles in U-Mo/Al dispersion fuel. Once optimized further, this instrument will be a powerful tool for investigating irradiated dispersion fuels in terms of fission product distributions in fuel matrices, and the changes in fuel particle size or shape after irradiation.

• Clinical Nutrition Research
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• v.12 no.4
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• pp.245-256
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• 2023

A randomized, double-blind, placebo-controlled trial was conducted to confirm whether collagen peptide supplementation for 12 week has a beneficial effect on body fat control in older adults at a daily physical activity level. Participants were assigned to either the collagen group (15 g/day of collagen peptide) or the placebo group (placebo drink). Body composition was measured by bioelectrical impedance analysis (BIA) and dual-energy X-ray absorptiometry (DEXA). In total, 74 participants (collagen group, n = 37; placebo group, n = 37) were included in the final analysis. The collagen group showed a significant reduction in total body fat mass compared with the placebo group, as evidenced by both BIA (p = 0.021) and DEXA (p = 0.041) measurements. Body fat mass and percent body fat of the whole body and trunk reduced at 12 weeks compared with baseline only in the collagen group (whole body: body fat mass, p = 0.002; percent body fat, p = 0.002; trunk: body fat mass, p = 0.001; percent body fat, p = 0.000). Total fat mass change (%) (collagen group, -0.49 ± 3.39; placebo group, 2.23 ± 4.20) showed a significant difference between the two groups (p = 0.041). Physical activity, dietary intake, and biochemical parameters showed no significant difference between the groups. The results confirmed that collagen peptide supplementation had a beneficial effect on body fat reduction in older adults aged ≥ 50 years with daily physical activity level. Thus, collagen peptide supplementation has a positive effect on age-related changes.

• Korean Journal of Community Nutrition
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• v.12 no.4
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• pp.477-488
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• 2007

Prevalence of an obese population has been increasing in Korea. Obesity is considered a major risk factor for chronic degenerative diseases. Specifically, prevalence of obesity is prominent for adult woman in Korea. In many weight control programs, weight change did not often show any beneficial effects for health. These facts discourage people in the program. Thus in this study, the anthropometry, blood pressure, serum biochemical indices and dietary habits were compared by percent body fat change for adult women to show the beneficial effects of the weight control program. Study subjects were 134. Measurements were done before and after the weight control program. Percent Body Fat (PBF) was measured by bioelectrical impedance analysis. Using PBF changes, subjects were grouped as I (more than 1% increase), M (${\pm}1%$ change), and D (more than 1% decrease). Data were analyzed using SPSS 12.0 program. Among the 134 participants, 13 increased their weight and 100 decreased. For PBF, 19 increased and 59 decreased. Statistical significant differences were shown for anthropometric assessments before and after for all weight, fat mass, percent body fat, waist-hip ratio and body mass index. I had increases, and D shows decreases. But the difference of D is large than M. Systolic and diastolic blood pressures decreased in all groups (p < 0.05). Fasting blood glucose decreased in all groups but were statistically significant only in D. Also triglyceride decreased in D (p < 0.05). Thus health conditions showed desirable changes in I < M < D in order. Dietary habit changes were desirable with only D. Weight, BMI and other indicators for obesity is not the real indicator for PBF. Recently it is easy to measure PBF. Thus, for weight control programs and to show benefits of the program, PBF is a good indicator for adult women in Korea.