• Structural Engineering and Mechanics
• /
• v.56 no.3
• /
• pp.385-407
• /
• 2015

This paper deals with the problem of the global stabilization for a class of tension leg platform (TLP) nonlinear control systems. It is well known that, in general, the global asymptotic stability of the TLP subsystems does not imply the global asymptotic stability of the composite closed-loop system. Finding system parameters for stabilizing the control system is also an issue need to be concerned. In this paper, we give additional sufficient conditions for the global stabilization of a TLP nonlinear system. In particular, we consider a class of NN based Takagi-Sugeno (TS) fuzzy TLP systems. Using the so-called parallel distributed compensation (PDC) controller, we prove that this class of systems can be globally asymptotically stable. The proper design of system parameters are found by a swarm intelligence algorithm called Evolved Bat Algorithm (EBA). An illustrative example is given to show the applicability of the main result.

• The Korean Journal of Applied Statistics
• /
• v.29 no.4
• /
• pp.699-706
• /
• 2016

Outlier detection methods without performing a test often do not succeed in detecting multiple outliers because they are structurally vulnerable to a masking effect or a swamping effect. This paper considers testing procedures supplemented to a clustering-based method of identifying the group with a minority of the observations as outliers. One of general steps is performing a variety of t-test on individual outlier-candidates. This paper proposes a sequential procedure for searching for outliers by changing cutoff values on a cluster tree and performing a test on a set of outlier-candidates. The proposed method is illustrated and compared to existing methods by an example and Monte Carlo studies.

• Nutrition Research and Practice
• /
• v.15 no.2
• /
• pp.203-212
• /
• 2021

BACKGROUND/OBJECTIVES: The branched-chain amino acids (BCAA), including isoleucine, leucine, and valine, promote muscle protein synthesis. However, obesity may interfere with protein synthesis by dysregulating mitochondrial function in the muscles. This study aimed to examine the association between dietary intake levels of BCAA and skeletal muscle mass index (SMI) in middle-aged participants, and the effect of obesity/abdominal obesity on this association. SUBJECTS/METHODS: The data of 3,966 men and women aged 50-64 years who participated in the 2008-2011 Korea National Health and Nutrition Examination Survey were analyzed. Intake levels of energy-adjusted dietary amino acids were obtained using a 24-hour dietary recall. SMI was calculated by dividing the appendicular skeletal muscle mass by body weight (kg) and multiplying the result by 100%. Multivariable general linear models were used to analyze the association of dietary BCAA intake levels with SMI. RESULTS: The beneficial effects of energy-adjusted dietary BCAA intakes on SMI were greater in the non-obesity/non-abdominal obesity groups; however, no significant associations were observed in the obesity/abdominal obesity groups (P > 0.05). CONCLUSIONS: Healthy weight and sufficient intake of dietary BCAA are recommended to maintain muscle mass.

• Journal of Environmental Health Sciences
• /
• v.49 no.1
• /
• pp.1-10
• /
• 2023

Low-dose radiation exposure has received considerable attention because it reflects the general public's type and level of exposure. Still, controversy remains due to the relatively unclear results and uncertainty in risk estimation compared to high-dose radiation. However, recent epidemiological studies report direct evidence of health effects for various types of low-dose radiation exposure. In particular, international nuclear workers' studies, CT exposure studies, and children's cancer studies on natural radiation showed significantly increased cancer risk among the study populations despite their low-dose radiation exposure. These studies showed similar results even when the cumulative radiation dose was limited to an exposure group of less than 100 mGy, demonstrating that the observed excess risk was not affected by high exposure. A linear dose-response relationship between radiation exposure and cancer incidence has been observed, even at the low-dose interval. These recent epidemiological studies include relatively large populations, and findings are broadly consistent with previous studies on Japanese atomic bomb survivors. However, the health effects of low-dose radiation are assumed to be small compared to the risks that may arise from other lifestyle factors; therefore, the benefits of radiation use should be considered at the individual level through a balanced interpretation. Further low-dose radiation studies are essential to accurately determining the benefits and risks of radiation.

• Geophysics and Geophysical Exploration
• /
• v.16 no.1
• /
• pp.36-44
• /
• 2013

We conducted the airborne magnetic and radiometric survey for the characterization of the black shale related and pyrometamorphic uranium deposits distributed in Geumsan area. For the successful characterization of the uranium deposits, the general geological and structural geological features were investigated based on the lithological and linear feature analysis to individual magnetic and radiometric data as the first step. Lithological analysis from the magnetic reduction to the pole and downward continuation map revealed that prominent positive anomalies caused by black and dark gray slate member were clearly recognized as magnetic sources. These results indicate that magnetic survey, even though it is not a direct method for the detection of uranium, can be a useful tool in uranium detection. By the linear feature analysis based on 2nd vertical derivative and curvature map, two linearments corresponded the gray hornfels and black slate member were extracted and in succession, the additional uranium potential zone was inferred. Final discrimination whether uranium-rich or not was confirmed by radiometric and uranium anomaly map. From these analysis, we finally concluded that uranium deposit originated by pyrometamorphic process was confined near the intrusive area only. On the contrary, it was found that black shale related uranium deposit is distributed and extended through out the entire survey area with south-west to north-east direction. In addition, from the linear feature analysis based on radiometric total anomaly map, the typical discontinuous characteristics were recognized in areas where uranium-contained linearments cross the faults. From the above discussion, we concluded that airborne magnetic and radiometric survey are complementary to each other. So it is preferable to carry out simultaneously for the efficient data processing and fruitful interpretation.

• Korean Journal of Clinical Laboratory Science
• /
• v.50 no.4
• /
• pp.484-491
• /
• 2018

Primer $Sj{\ddot{o}}gren's$ Syndrome (pSS) is an autoimmune/inflammatory illness. The platelet indices (PIs) indicate the inflammatory response and activity/severity of many diseases. A vitamin D deficiency is accompanied by the increased tendency of autoimmune diseases. This study investigated whether the vitamin D levels are related to the altered platelet indices in pSS. A total of 261 individuals were included in this analytical cross-sectional study. The laboratory data of pSS patients were evaluated and the relationship between the PIs and vitamin D status was examined. According to these findings, in patients with pSS, the vitamin D levels were lower than the healthy control group (P<0.05). The vitamin D levels were negatively associated with PDW (P=0.012), but positively correlated with PCT (P<0.001). The cut-off point was obtained with receiver operating characteristics (ROC) curves for PDW: 12.53 (AUC 0.921, sensitivity 90%, specificity 85%), for PCT; 0.29 (AUC 0.660, sensitivity 68%, specificity 55%). In multivariate linear regression analysis, the most significant parameters for the effects of PDW are the following: vitamin D (${\beta}=-0.373$; t=-2.626; sig.=0.013) and plateletcrit (${\beta}=-0.308$; t=-2.13; sig.=0.040). A vitamin D deficiency may be accompanied by changes in PIs in pSS. A higher PDW and lower PCT supports the underlying inflammation, which may be vitamin D related useful parameters to consider in approaching to pSS.

• Journal of Korean society of Dental Hygiene
• /
• v.19 no.5
• /
• pp.699-713
• /
• 2019

Objectives: This study aimed to identify the relationships of oral and systemic health-related characteristics with health-related quality of life (EQ-5D) in the elderly, and factors related to quality of life were compared according to age subgroups classified as either younger (young-old) or older (old-old) than 75 years of age. Methods: Data acquired by the Sixth Korean National Health and Nutrition Examination Survey(KNHANES) from 2013 to 2015 were used, and the research target was 3,124 people aged 65 years or older. A complex samples general linear model was used to identify health-related quality of life factors. Results: Education, economic activity, depression, stress, regular walking, self-rated oral health, pronunciation problems, and unmet dental care had significant effects on quality of life in both young-old and old-old participants. Marriage, income, number of systemic diseases, sleeping, and chewing inconveniences were significant factors for the young-old but not in the old-old participants. Instead, obesity and drinking were identified as significant factors in the old-old participants. Conclusions: We reaffirmed that factors affecting health-related quality of life in older adults differed by age group. We also confirmed the impact of oral health-related characteristics on this quality. Therefore, to improve quality of life for older adults, it would be efficient to divide groups by age and develop and implement programs that take relevant factors into consideration.

• Journal of Preventive Medicine and Public Health
• /
• v.22 no.2 s.26
• /
• pp.215-222
• /
• 1989

The relationship between cadmium level and mental retardation was investigated. The 297 subjects with mental retardation were drawn from two schools providing special educational services, one, consisted of children living in an orphan home, another, children with parents. The 117 control subjects were drawn from whom had got average or above average academic achivement in a general elementary school. Hair sample was taken from the nape of the neck and the cadmium and zinc analysis were carried out on an atomic absorption spectrophotometer (IL 551). Children in the retarded group had significantly higher cadmium levels compared with control but not in zinc levels. There was no relationship between metal concentrations and age except control male group, which showed significant positive linear relationship in zinc, and there was no difference between sex in both metal except the male orphan group in cadmium. In the orphan group, there was relationship between severity of retardation and cadmium concentration in both sex but not in retarded children with parents. No difference in cadmium levels between the group with Down's syndrome, one of causes of mental retardation, and the control group suggested the cadmium as a possible cause of mental retardation. In the case of accompanying autism, zinc level was significantly lower than that of other accompanying diseases. Although not establishing an etiologic relationship, findings of this study suggest that there are some influeces of cadmium on mental retardation, and call for a continuing study.

• Nutrition Research and Practice
• /
• v.14 no.4
• /
• pp.365-373
• /
• 2020

BACKGROUND/OBJECTIVES: To assess the longitudinal associations of the antioxidant capacity of zinc and body mass index (BMI) with serum uric acid (SUA) in South Korean children. SUBJECTS/METHODS: Using follow-up data from the Ewha Birth and Growth Cohort, we included subjects who were seen at 3 and 7 years of age (n = 183; 90 boys, 93 girls). Daily zinc intake and BMI were assessed at 3 and 7 years of age. SUA measured at 7 years was used as the outcome variable. Using a general linear model, the effects of dietary zinc intake and BMI on SUA were assessed. We also assessed the combined effect of early dietary zinc intake and BMI on SUA in children. RESULTS: The dietary zinc intake at 3 years of age was negatively correlated (ρ = -0.18, P = 0.04), whereas the BMI at 7 years of age was positively correlated (r = 0.18, P = 0.01), with the SUA level at 7 years of age. The dietary zinc intake level at 3 years of age and the BMI level at 7 years of age were, together, significantly related to SUA in children at 7 years of age. SUA was lower in group 1 (normal-weight, high-zinc group) than in the other two groups (group 2: normal-weight, low-zinc and overweight, high-zinc group; and group 3: overweight, low-zinc group). Our results demonstrate the combined effect of zinc intake and BMI on SUA. The combined association remained significant in both the crude and adjusted models (P < 0.01). CONCLUSIONS: SUA was related to combined BMI and dietary zinc intake, and increased zinc intake and normal body weight had a beneficial effect on reducing SUA in children.

• Journal of Sasang Constitution and Immune Medicine
• /
• v.21 no.3
• /
• pp.48-62
• /
• 2009

1. Objectives: The purpose of this study was to analyze the physical and psychological characteristics of each Sasang type groups which were classified by Sasang medicine specialist. 2. Methods: The subjects were 115 (85.2% of male) university students with $26.8\pm5.4$ yrs. of age and $12.9\pm1.7$ yrs. of education. We can get 30 of Soyang type, 39 of Taeeum type, 46 of Soeum type after the Sasang type classification. Their physical characteristics were measured with Bioelectrical Impedance Analysis (Inbody 720, Biospace, Seoul), and psychological characteristics with Temperament and Character Inventory (Maumsarang, Seoul). The general linear model (SPSS 12.0, SPSS Inc, Chicago) were used for the analysis with gender and age as covariance. 3. Results and Conclusions: Taeeum type group ($75.64\pm13.01$, $26.12\pm4.16$, $15.74\pm2.42$, $11.30\pm1.80$, $3.93\pm0.62$, $18.43\pm7.70$) showed significantly bigger weight, intra-cellular water, extra-cellular water, protein, mineral, body fat mass than Soeum type group ($61.32\pm8.56$, $22.54\pm3.87$, $13.70\pm2.15$, $9.74\pm1.68$, $3.35\pm0.51$, $10.79\pm3.97$). In obesity degree such as Body Mass Index and Waist-hip ratio, and circumference measures in chest, waist and hip, we found significant differences in the order of Taeeum>Soyang>Soeum. As a psychological perspectives Soyang type group ($41.90\pm13.32$) has higher NS (Novelty-Seeking) score than Soeum type group ($35.22\pm11.22$) with marginal significance (p=0.052). In sub-scale measurements Soeum type group ($10.61\pm3.69$) has significantly lower value than other two groups in P3 (Ambition). The results of present study showed that Taeeum type by specialist has same physical characteristics as previously reported QSCC II based studies. Temperament profile of each Sasang type group will serve as an important evidence for further study showing that the Sasang typology has biological basis.