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Kwak D.-S.,Pohang University of Science and Technology | Kim K.-J.,Pohang University of Science and Technology | Lee M.-S.,Cheju Halla College
International Journal of Production Research | Year: 2010

Industries such as automotive, LCD, PDP, semiconductor and steel produce products through multistage manufacturing processes. In a multistage manufacturing process, performances of stages are not independent. Therefore, the relationship between stages should be considered when optimising the multistage manufacturing process. This study proposes a new procedure of optimising a multistage manufacturing process, called multistage PRIM (patient rule induction method). Multistage PRIM extends the scope of process optimisation from a single stage to the multistage process, and it can use the information encapsulated in the relationship between stages when maximising each stage's performance. A case study in a multistage steel manufacturing process is conducted to illustrate the proposed procedure. © 2010 Taylor & Francis.


Sharma S.K.,Cheju Halla College | Inamdar A.I.,Dongguk University | Im H.,Dongguk University | Kim B.G.,Cheju Halla College | Patil P.S.,Shivaji University
Journal of Alloys and Compounds | Year: 2011

Nano-crystalline zinc oxide thin films were electrosynthesized with an aqueous zinc acetate [Zn(CH3COO)2·2H2O] solution on to FTO coated glass substrates. Two different electrochemical baths were used, namely (i) without an organic surfactant and (ii) with an organic surfactant, viz. PVA (poly-vinyl alcohol) and SDS (sodium dodecyl sulfate). The organic surfactants played an important role in modifying the surface morphology, which influenced the size of the crystallites and dye-sensitized solar cell (DSSC) properties. The vertically aligned thin and compact hexagonal crystallites were observed with SDS mediated films, while the grain size in the films without an organic surfactant was observed to be ∼150 nm. The conversion efficiencies of the ZnO:SDS:Dye and ZnO:PVA:Dye thin films were observed to be 0.49% and 0.27%, respectively. © 2010 Elsevier B.V. All rights reserved.


Oh I.-H.,Korea University | Yoon S.-J.,Korea University | Kim E.-J.,Cheju Halla College
Journal of the Korean Medical Association | Year: 2011

The disability adjusted life year (DALY), a single indicator of the burden of disease, is widely used to measure the burden of diseases, injuries, and risk factors. In this study, we review the relative sizes of the burden of disease worldwide and the characteristics of the burden of disease of the Korean population. Future research directions for study of the burden of disease in Korea are also suggested. In the Korean population, diabetes mellitus was the leading cause of the burden of disease (970 DALYs per 100,000 population) in 2002, followed by cerebrovascular disease (937 DALYs per 100,000 population) and asthma (709 DALYs per 100,000 population), which differed with the leading causes of the burden of disease globally: unipolar depressive disorder, ischemic heart disease, and cerebrovascular disease. In 2007, cirrhosis of the liver in males and cerebrovascular disease in females became the leading causes of the burden of disease of the Korean population with the epidemiologic transition. Despite the methodological difference with global burden of disease study, these findings represent the characteristics of the burden of disease in Korea. Though many studies have been conducted to measure the burden of disease in Korea, there is a need to go beyond these to combine policymaking for resource allocation, such as cost effectiveness analysis, with burden of disease studies. © Korean Medical Association.


Kang Y.K.,Chungbuk National University | Byun B.J.,Chungbuk National University | Park H.S.,Cheju halla College
Biopolymers | Year: 2011

Conformational preferences and prolyl cis-trans isomerizations of the (2S,4S)-4-methylproline (4S-MePro) and (2S,4R)-4-methylproline (4R-MePro) residues are explored at the M06-2X/cc-pVTZ//M06-2X/6-31+G(d) level of theory in the gas phase and in water, where solvation free energies were calculated using the implicit SMD model. In the gas phase, the down-puckered γ-turn structure with the trans prolyl peptide bond is most preferred for both Ac-4S-MePro-NHMe and Ac-4R-MePro-NHMe, in which the C7 hydrogen bond between two terminal groups seems to play a role, as found for Ac-Pro-NHMe. Because of the C7 hydrogen bonds weakened by the favorable direct interactions between the backbone C=O and H-N groups and water molecules, the 4S-MePro residue has a strong preference of the up-puckered polyproline II (PPII) structure over the down-puckered PPII structure in water, whereas the latter somewhat prevails over the former for the 4R-MePro residue. However, these two structures are nearly equally populated for Ac-Pro-NHMe. The calculated populations for the backbone structures of Ac-4S-MePro-NHMe and Ac-4R-MePro-NHMe in water are reasonably consistent with CD and NMR experiments. In particular, our calculated results on the puckering preference of the 4S-MePro and 4R-MePro residues with the PPII structures are in accord with the observed results for the stability of the (X-Y-Gly)7 triple helix with X = 4R-MePro or Pro and Y = 4S-MePro or Pro. The calculated rotational barriers indicate that the cis-trans isomerization may in common proceed through the anticlockwise rotation for Ac-4S-MePro-NHMe, Ac-4R-MePro-NHMe, and Ac-Pro-NHMe in water. The lowest rotational barriers become higher by 0.24-1.43 kcal/mol for Ac-4S-MePro-NHMe and Ac-4R-MePro-NHMe than those for Ac-Pro-NHMe in water. © 2010 Wiley Periodicals, Inc. Biopolymers 95: 51-61, 2011.


Oh I.-H.,Korea University | Yoon S.-J.,Korea University | Seo H.-Y.,Korea University | Kim E.-J.,Cheju Halla College | Kim Y.A.,Korea University
BMC Musculoskeletal Disorders | Year: 2011

Background: Musculoskeletal diseases are becoming increasingly important due to population aging. However, studies on the economic burden of musculoskeletal disease in Korea are scarce. Therefore, we conducted a population-based study to measure the economic burden of musculoskeletal disease in Korea using nationally representative data. Methods. This study used a variety of data sources such as national health insurance statistics, the Korea Health Panel study and cause of death reports generated by the Korea National Statistical Office to estimate the economic burden of musculoskeletal disease. The total cost of musculoskeletal disease was estimated as the sum of direct medical care costs, direct non-medical care costs, and indirect costs. Direct medical care costs are composed of the costs paid by the insurer and patients, over the counter drugs costs, and other costs such as medical equipment costs. Direct non-medical costs are composed of transportation and caregiver costs. Indirect costs are the sum of the costs associated with premature death and the costs due to productivity loss. Age, sex, and disease specific costs were estimated. Results: Among the musculoskeletal diseases, the highest costs are associated with other dorsopathies, followed by disc disorder and arthrosis. The direct medical and direct non-medical costs of all musculoskeletal diseases were $4.18 billion and $338 million in 2008, respectively. Among the indirect costs, those due to productivity loss were $2.28 billion and costs due to premature death were $79 million. The proportions of the total costs incurred by male and female patients were 33.8% and 66.2%, respectively, and the cost due to the female adult aged 20-64 years old was highest. The total economic cost of musculoskeletal disease was $6.89 billion, which represents 0.7% of the Korean gross domestic product. Conclusions: The economic burden of musculoskeletal disease in Korea is substantial. As the Korean population continues to age, the economic burden of musculoskeletal disease will continue to increase. Policy measures aimed at controlling the cost of musculoskeletal disease are therefore required. © 2011 Oh et al; licensee BioMed Central Ltd.


Li Y.,Jeju National University | Bok T.-H.,Jeju National University | Yang J.-H.,Interdisciplinary Postgraduate Program in Biomedical Engineering | Yang J.-H.,Cheju Halla College | And 2 more authors.
Ultrasound in Medicine and Biology | Year: 2011

The objective of this research is to study the cyclic variations in echogenicity (CVE) as an acute response to smoking. CVEs, caused by the aggregation of red blood cells (RBC) were measured from the cross-sectional images of the common carotid artery using coded harmonic imaging of a commercial ultrasound system. The amplitude of the CVE (Acve) was analyzed among 28 smokers before and after smoking. Acve was increased in 22 smokers and decreased in six smokers after 1-2 cigarettes were smoked. Heart rate (HR) was also estimated from the ultrasonic images before and after smoking. The smokers were optimally divided into two clusters with respect to the change in Acve and the intrinsic characteristics of smokers (i.e., daily consumed cigarettes and smoking years) through a two-step cluster analysis (TSCA). The increase in Acve after smoking was significantly higher in the heavy smoker cluster compared with the light smoker cluster. The results suggest that the acute changes in Acve in response to smoking are different between heavy smokers and light smokers. This preliminary study demonstrates the potential application of coded harmonic ultrasound imaging to detect or characterize RBC aggregation. In addition, the results may be useful for understanding the acute physiologic changes caused by smoking. (E-mail: paeng@jejunu.ac.kr). © 2011 World Federation for Ultrasound in Medicine & Biology.


Lee Y.-H.,Korea University | Yoon S.-J.,Korea University | Kim E.-J.,Cheju Halla College | Kim Y.-A.,Korea University | And 2 more authors.
Allergy and Asthma Proceedings | Year: 2011

Understanding the magnitude of the economic impact of an illness on society is fundamental to planning and implementing relevant policies. South Korea operates a compulsory universal health insurance system providing favorable conditions for evaluating the nationwide economic burden of illnesses. The aim of this study was to estimate the economic costs of asthma imposed on Korean society. The Korean National Health Insurance claims database was used for determining the health care services provided to asthma patients defined as having at least one inpatient or outpatient claim(s) with a primary diagnosis of asthma in 2008. Both direct and indirect costs were included. Direct costs were those associated directly with treatment, medication, and transportation. Indirect costs were assessed in terms of the loss of productivity in asthma patients and their caregivers and consisted of morbidity cost, mortality cost, and caregivers' time cost. The estimated cost for 2,273,290 asthma patients in 2008 was $831 million, with an average per capita cost of $336. Among the cost components, outpatient and medication costs represented the largest cost burden. Although the costs for children accounted for the largest proportion of the total cost, the per capita cost was highest among patients ≥50 years old. The economic burden of asthma in Korea is considerable. Considering that the burden will increase with the rising prevalence, implementation of effective national prevention approaches aimed at the appropriate target populations is imperative. Copyright © 2011, OceanSide Publications, Inc.


Kim H.-J.,Korea University | Kim Y.-A.,Korea University | Seo H.-Y.,Korea University | Kim E.-J.,Cheju Halla College | And 2 more authors.
Journal of the Korean Medical Association | Year: 2012

Stroke is a disease that causes a substantial economic burden. With the rapidly aging population in Korea, the prevalence of chronic diseases, including stroke, is expected to rise, along with associated health care expenditures. Therefore, we estimated the economic burden of stroke in Korea in 2010 using nationally representative data. We used a prevalence-based approach to estimate the cost of stroke by claims data from the Korean National Health Insurance. Data from the Korea Health Panel, the Korea National Statistical Office's records of causes of death, and Labor Statistics were used to calculate direct non-medical costs and indirect costs. Direct costs included direct medical costs and direct non-medical costs, and indirect costs were opportunity costs lost due to premature death and productivity loss. Total costs were estimated by adding age- and gender-specific costs. The total economic burden of stroke was $3.53 billion: $1.87 billion for hemorrhagic stroke and $1.66 billion for ischemic stroke. The direct costs were $1.74 billion and the indirect costs were $1.79 billion. By gender, males were burdened at $2.19 billion, while females bore $1.34 billion of the total burden. Stroke imposes a huge economic burden, as indicated by the fact that the costs of stroke increased by 4.4% from 2005 to 2010, and the estimated cost was 0.35% of gross domestic product. Therefore, effective prevention programs and treatments are needed to reduce the economic burden of stroke in Korea. © Korean Medical Association.


Shin Y.-K.,Yeonkang Hospital | Kim D.J.,Catholic University of Korea | Jung-Choi K.,Seoul Womens University | Son Y.-J.,Cheju Halla College | And 3 more authors.
Scandinavian Journal of Forest Research | Year: 2013

Several studies have reported that exercise and meditative activities in a forest are more effective than the same activities performed in an urban area. However, few studies have compared the direct effects of exercise to those of meditative activity in a forest and indoors. This study aimed to identify how the effects of the same activity might differ when performed in a forest as opposed to indoors, as well as how the effects of meditative and athletic activities in the same environment might differ. We recruited 139 females between 18 and 25 years of age and distributed the subjects into four groups by random allocation: athletic walking in the gymnasium (AG), athletic walking in the forest (AF), meditative walking in the gymnasium (MG), and meditative walking in the forest (MF). We evaluated the subjects before and after walking, using the State-Trait Anxiety Inventory-X, Rosenberg Self-Esteem Scale, and Happiness Index for Koreans. Meditative walking had greater effectiveness on the psychological aspects than athletic walking did in the same environment. Also, walking in the forest increased happiness to a greater degree than walking in the gymnasium at the same pace. Especially meditative walking in the forest was the most effective at increasing happiness. © 2013 Copyright Taylor and Francis Group, LLC.


Seo H.-Y.,Korea University | Yoon S.-J.,Korea University | Kim E.-J.,Cheju Halla College | Oh I.-H.,Korea University | And 2 more authors.
Rheumatology International | Year: 2013

Understanding the impact of rheumatic heart disease (RHD) has become increasingly important among aging populations around the world, and Korea is no exception. This study was conducted to estimate total annual patient costs associated with RHD in Korea for 2008 using nationally representative data. The subjects were South Korean citizens with RHD (ICD-10 codes I01-I09). The primary information for this study was obtained from claims data compiled by the National Health Insurance Corporation of Korea. Direct medical care costs were estimated using expenses paid by insurers and patients for non-covered care and pharmaceutical costs. Direct non-medical costs were estimated using data on transportation costs for hospital visits and costs for caregivers. Indirect costs included the costs of productivity loss and premature death in RHD patients. The economic burden of RHD in 2008 was estimated at $67.25 million US dollars. The indirect costs amounted to 39.04 % (US $26.26 million) of the total RHD costs. When stratified by age, the costs incurred by the group of patients older than 60 years were US $31.63 million. The prevalence of the disease in the same age group was 791.07 cases per 100,000 people. This study confirms that the prevalence of RHD was highest in patients older than 60 years in 2008. Furthermore, the patterns of disease in South Korea were similar to patterns observed in other high-income countries. These findings indicate that secondary prevention strategies for the early detection of RHD are needed in South Korea. © 2012 Springer-Verlag Berlin Heidelberg.

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