• Communications for Statistical Applications and Methods
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• v.16 no.1
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• pp.85-102
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• 2009

This paper derives conversion formulas from yearly-based absolute rates of decrements to monthly-based rates of decrement due to cause J under fractional age distributions. Next, it suggests conversion formulas from monthly-based absolute rates of decrements to monthly-based rates of decrement due to cause j under fractional age distributions. In addition, it applies the conversion formulas including a dynamic lapse rate model to variable annuities. Some numerical examples are discussed.

• The Korean Journal of Applied Statistics
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• v.21 no.6
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• pp.1045-1063
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• 2008

This paper derives conversion formulas from yearly-based absolute rates of decrements to monthly-based rates of decrement due to cause j under FI (fractional age independence) assumption that is a generalization of UDD assumption. Next, it suggests conversion formulas from monthly-based absoluterates of decrements to monthly-based rates of decrement due to cause j under FI assumption. In addition, it calculates conversion formulas from yearly-based rates of decrement due to cause j to the corresponding monthly-based absolute rates of decrements under FI assumption. Some numerical examples are discussed.

• The Korean Journal of Applied Statistics
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• v.26 no.3
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• pp.549-568
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• 2013

This paper discusses conversion methods between multiple decrement models and associated single decrement models. One of most popular assumptions on fractional age is UDD(uniform distribution of decrement) or constant force of mortality in actuarial practice. Instead of these assumptions, this paper suggests cubic spline interpolation to approximate the distribution of fractional age with the continuous force of decrements. Conversion formulas are derived. The comparisons of these two methods based on the numerical data show that the cubic spline interpolation approach is more accurate.

• The Korean Journal of Applied Statistics
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• v.25 no.1
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• pp.1-13
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• 2012

An assumption for fractional ages should be made to obtain the net premium of the whole life insurance payable at the moment of death based on the life table. Most existing studies adopt the assumption of the uniform distribution(UDD) for the fractional ages. However, as seasonal changes may frequently lead to the deaths of elderly people, it is questionable whether the assumption of the uniform distribution is the most appropriate one for the entire age intervals. In this article, based on a real mortality data set, the appropriateness of UDD assumption for the entire age intervals is examined. And then we propose a more suitable model for fractional ages. We analyze the effect of UDD assumption through the net premium and the corresponding risk when the true distribution for the fractional ages is not uniform.

• Journal of the Korean Geographical Society
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• v.46 no.4
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• pp.480-500
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• 2011

This paper aims to describe the rapid growth of the one-person households in terms of the socio-economic demographic perspectives during the period of 1995-2005 and to analyze the spatial distribution patterns based on different characteristics of one-person households. The increase in the divorce ratio in the middle-aged, the growth of unmarried people the young generation, and the increase of life expectancy in the old generation are explanatory factors for the rise and diversification of one-person households in Korea. The rapid increase of one-person households is accompanied by a diversification in their age, gender, marital status, education level. Uneven distribution of one-person households depends on their age, level of education and dwelling type. Highly educated young adults residing in their own apartment are generally concentrated in major cities, whereas senior citizen with their own single house who lives alone are mostly in rural area. One-person households of the highly educated young adults are significantly polarized in the light of their the living standards. In particular, metropolitan area or big cities are mixed with those who have their own apartment and are financially capacity and with those who rent in a detached single house. As such, one-person households have considerably heterogeneous characteristics. Therefore, each local government will face different economic and social problems based on which group of one-person households are increasing and where they are concentrated in. To this extent, the local government should have differentiated welfare policy according to its own respect.

• Korean Journal of Veterinary Research
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• v.40 no.3
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• pp.421-430
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• 2000

The regional distribution and relative frequency of the pancreatic polypeptide (PP)-immunoreactive cells in the pancreas of the Korean native goat (Capra hircus) were studied by immunohistochemical methods (PAP methods) using specific antisera against to PP during developmental stage, fetus, neonate, 1-month-old, 6-month-old and adult. The different regional distribution and relative frequency of PP-immunoreactive cells in the pancreas of Korean native goat were observed during development. In the exocrine portions, they were detected in the all ages and distributed in the interacinar regions. PP-immunoreactive cells were increased from neonate to 1-month-old but thereafter decreased with developmental stage. In the pancreatic duct, PP-immunoreactive cells were demonstrated from 1-month-old but they were decreased with developmental stages in these regions. These cells were observed in the subepithelial connective tissue of the pancreatic duct with a few frequencies in 1-and 6-month-old. However, they were located in the interepithelial cells of the pancreatic duct in the adult with rare frequency. In the endocrine portion (pancreatic islets), PP-immunoreactive cells were observed from neonate, and the regional distribution of PP-immunoreactive cells from 1-month-old was divided into two patterns : dispersed 1) in the marginal regions of the pancreatic islets with moderate or a few frequencies, and 2) in the whole pancreatic islets (in a case of 1-month-old) or in the central cores (in a case of 6-month-old and adult) with numerous frequency. In conclusion, the different regional distribution and relative frequency of PP-immunoreactive cells in the pancreas of the Korean native goat were observed during development. It is suggested that the changing of feeding habits and physiological conditions during different developmental stages may cause these differences.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.59-65
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• 2012

Purpose: The purpose of this study was to determine the distribution and correlation of accommodative lag with refractive error. Method: We had tested the clinical refraction and the accommodative lag in clinically normal 49 young adults (total 98 eyes) aged 18 to 25 years without abnormal binocular function. Monocular and binocular accommodative lag were tested with 0.50 D cross-cylinder lens and near vision test chart which had cross-hairs after full correction of LogMAR visual acuity over 0.05. Results: There was no statistical differences in monocular accommodative lag between right ($0.64{\pm}0.64$ D) and left eye ($0.63{\pm}0.64$)(p=0.858). The accommodative lag of male was higher than female and the range of the value was broader than female in binocular accommodative lag (p=0.015). The wider the inter-pupillary distance was, the higher the accommodative lag was (p=0.003). However, there were no differences with age (p=0.800) and dominant eye (p=0.402). The ranges of accommodative lag of low, middle, and high myopia were 0.75 ~ -0.25 D, 1.25 ~ -0.50 D, and 1.50 ~ -0.75 D, respectively, and the regression was 'y = -0.03953x+0.09205'. Conclusions: These data suggest that clinically normal young adults with high amounts of refractive error have more variable accommodative lag and increased spherical equivalent refraction.

• Journal of Chest Surgery
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• v.31 no.6
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• pp.604-609
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• 1998

Trauma to the thorax represents a significant portion of injuries seen in an inner-city emergency room. Although most of these patients may be sucessfully managed without thoracotomy, a certain percentage requires operative intervention either immediately or within several hours. 126 records of patients who had early thoracotomy for chest trauma from March 1986, to June 1997, in the Department of Thoracic and Cardiovascular Surgery in Masan Samsung General Hospital were reviewed. There were 96 males and 30 females whose ages ranged from 4 to 72 years, with a mean age of 32.8 years. The modes of injury were as follows : stab wounds, 55 cases(44%), blunt trauma, 70 cases(55%), and gunshot wound, 1 case(1%). Immediate operation was performed in 105 cases(84%) and delayed operation in 21 cases(16%). Indications that operation was necessary were hemorraging and shock in 66 cases(52%), cardiac tamponade in 27 cases(21%), and rupture of the diaphragm in 33 cases(27%). Most of these patients were sucessfully treated but 21 cases were resulted in death. The mortality rate was 16.6% and common causes of death were irreversible shock and hypoxia.

• Journal of agricultural medicine and community health
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• v.31 no.2
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• pp.145-156
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• 2006

Objectives: Health behaviors are related to each other, or they may be essentially dependent upon each other. Hence the overall health behaviors of a given population could be better described in terms of health lifestyle patterns. This paper tried to classify such patterns in a sample population and suggest the socioeconomic and demographic characteristics of each groups. Methods: A sample population comprised of 2,775 adults who reported their health behaviors in a public health survey were classified according to their smoking, drinking, diet, and exercise related pattern of behaviors. Clustering analysis was used to classify them. Results: Six health lifestyle patterns were identified. Individuals in the passive lifestyle cluster (48.3%) had no active health promoting activities, but did avoid risk taking health behaviors. 24.8% of the sample (Health promoting lifestyle) had an overall healthy lifestyle. 13.5% of the sample were in the smoking cluster, and 8.4% were in the alcohol drinking cluster. The hedonic lifestyle (4.5%) was characterized by heavy smoking, alcohol drinking and poor diet and exercise. 0.7% of the sample (Smoking-Drinking lifestyle) had heavy smoking and drinking, but good diet and exercise. Each group could be characterized by sex, age, and income. Conclusions: A population sample of Seoul adults were successfully clustered into six health lifestyles. The socioeconomic and demographic characteristics were suggested for the characterization of the each health lifestyle groups. We can approach to a certain target population with specific strategy.

• Clinical and Experimental Pediatrics
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• v.49 no.4
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• pp.424-430
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• 2006

Purpose : Juvenile rheumatoid arthritis(JRA) is one of the most common rheumatic diseases of childhood and is an important cause of short- and long-term disability. The purpose of this study was to determine the disease course and outcome in childhood patients with JRA. Methods : Fifty nine patients with JRA who were diagnosed and treated in the Department of Pediatrics, Asan Medical Center from August 1990 to November 2004 were enrolled in this study. Sex, age, type, affected joints, extra-articular manifestations, laboratory and radiologic findings, treatments, and outcomes of JRA patients were reviewed retrospectively. Results : Among JRA patients, 32.2 percent had pauciarticular type, 30.5 percent had polyarticular type and 37.3 percent had systemic type. The ratio of boys to girls was 1.7 : 1 and the mean age at onset was $9.3{\pm}3.7$(1.3-15.9) years. The most commonly affected joints were knee, ankle and wrist. The extra-articular manifestations observed were fever, rash, myalgia and lymph node enlargement, etc. The main laboratory findings observed were leukocytosis, anemia, thrombocytosis, elevated ESR, and elevated CRP. Rheumatoid factor and antinuclear antibody(ANA) were positive in 5.3 percent and 18.0 percent. Nonsteroid anti-inflammatory drugs(NSAID) were used most frequently and methotrexate with or without steroids was added in 27.1 percent of patients unresponsive to NSAID. 88.1 percent of patients were cured without functional disability and only one patient was in functional status IV. One patient, who had pulmonary involvement, died. Conclusion : Our results showed an even distribution in type of onset, male predominance, older age of onset, low incidence of iridocyclitis, and low positivity of ANA in JRA patients; this differs from occidental data. This study may suggest regional differences and variability in disease groups of JRA among different racies, but further multi-center trials and large scale epidemiological studies are needed to confirm our conclusion.