• Journal of the Korean Statistical Society
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• v.26 no.1
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• pp.101-116
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• 1997

This is primarily an expository paper that presents several nonparametric procedures for testing exponentiality against certain monotonicity properties of the mean residual life function, tests against the trend change in such function attract a great deal of attention of late in reliability analysis. In this note, we present some of the known testing procedures regarding the behavior of mean residual life function. These tests are also compared in terms of asymptotic relative efficiency and empirical power against a few alternatives. The tests based on incomplete data are also briefly discussed.

• Journal of the Korean Statistical Society
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• v.21 no.2
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• pp.187-200
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• 1992

Samples are often found to be too heterogeneous to be explained by a one-parameter family of models in the sense that the implicit mean-variance relationship in such a family is violated by the data. This phenomenon is often called over-dispersion. The most frequently used method in dealing with over-dispersion is to mix a one-parameter family creating a two parameter marginal mixture family for the data. In this paper, we investigate performance of estimators such as maximum likelihood estimator, method of moment estimator, and maximum quasi-likelihood estimator in negative binomial and beta-binomial distribution. Simulations are done for various mean parameter and dispersion parameter in both distributions, and we conclude that the moment estimators are very superior in the sense of bias and asymptotic relative efficiency.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.1
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• pp.55-66
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• 1996

One-hour average concentrations of ground-level ozone from around 80 monitoring stations in Korea during 1991 to 1993 were analyzed to examine characteristics of the ozone concentration variations. Two types of variations were observed: one was for the Capital area typified by Kwanghwmun, and the other was for the south and east seashore region typified by Tongkwangyang. In the Capital area including Seoul, Inchon, Kyonggi-do and Chunchon, mean daily 1-hout maximum was the highest in June following high monthly averages in spring. But frequent precipitation prevented further rise of daily maximum in July and August even though there were frequent episodes of high concentration exceeding 100ppb. In the south and east seashore region, average concentration was the highest throughout the year, and daily maximum and minimum simultaneously changed owing to small contributions from photochemical reactions. The typical annual variation was spring peak, summer down, and fall rise. Spring peak accompanied an usual observations of background variations at remote sites in the Northern Hemisphere. Riess of average and daily maximum with lower daily minimum in fall were attributable to photochemical reactions.

• Journal of Korean Neurosurgical Society
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• v.48 no.1
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• pp.66-69
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• 2010

The management of lower cervical fractures in patients with ankylosing spondylitis (AS) differs from normal cervical fractures. Patients with AS are highly susceptible to extensive neurologic injuries and spinal deformities after cervical fractures from even minor traumatic forces. These injuries are uniquely complex, require careful imaging assessment, and aggressive surgical management to optimize spinal stability and functional outcomes.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.243-249
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• 1998

Radicoid structure of herbaceous communities in Mt. Kumbyung, Chunchon, Kangwon-Do was clarified emphasizing on the dominance of clonal plants in relation to vegetation development. In the total vegetation, 46% species identified were rhizomatous, 26% were species with tap roots, and 13% were stoloniferous species. Thus, all clonal species, including plants with bulb, corm and tuber, covered 62.8% of the total species. in the understory of Quercus, Pinus and Larix forests, 68.2% were clonal, which means 5% more compare to total vegetaion. Dominance of clonal plants became more conspicuous as their importance value was calculated. That is, they covered average 86% for the following three communities: 85% in Quercus, 95% in Pinus, and 76% in Larix, Especially, the rhizomatous plants were remarkable. Overall, clonal species dominated over the other radicoid types in terms of not only the number of species, but also the importance value. Dominance of these species was more peculiar in understory of forests, indicating the occupancy of clonal plants was related to the vegetation development.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.109-114
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• 2000

The purpose of the present study is to develope the estimation scheme for sensible heat flux by semi-empirical approach using routine meteorological data such as solar radiation and air temperature. To compare observed sensible heat flux with estimated sensible heat flux, the sensible heat fluxes were measured by three dimensional sonic anemometer-thermometer. The field observation was performed during 1 year from December 1, 1995 to November 30, 1996 on a rice paddy field in Chunchon basin. The heat fluxes were measured at a heights of 5m and mean meteorological variables were obtained at two levels, 2.5m(or 1.5m) and 10m. Since condition of rice paddy field such as, wetness of the field, roughness length, vary widely, we devided annual data to 5 periods. Comparing with two sensible heat fluxes, the results showed that the correlation coefficients were more than 0.86. Thus, we can conclude that the estimation method of sensible heat fluxes using routine meteorological data is practical and reliable enough.

• Plant Disease and Agriculture
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• v.5 no.1
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• pp.46-49
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• 1999

Bacterial blight occurred on the flowers, leaves, twigs and branches of apple trees (Malus domestica Borkh) in Chunchon, Kangwon-Do. Infected flowers and leaves turned brownish black, and they were fallen down or remained hanging in the trees. Under humid conditions during postblossom period, the casual bacterium spreaded along twigs and killed them. However, killing of branches was very rare. The symptoms on apple trees were very similar to symptoms of fire blight. But the causal organism isolated from the lesions was identified as Pseudomonas syringae based on physiological and chemical characteristics. This is the first described bacterium that causes apple shoot blight in Korea.

• The Korean Journal of Malacology
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• v.4 no.1
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• pp.42-49
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• 1988

The chromosome of Cipangopaludina chinensis malleata Chunchon area in 1988 was analysed by using aceto-orcein squash techniques of spermatogonial tissues to obtain mitotic and meiotic chromosomes. The chromosome cycle did not differ, in general, from that found in other snails, C. chinensis malleata has 18 diploid chromosomes and they were identified and classified into 2 groups. The mitotic chromosome complement of this species consists of 2 pairs of metacentric and 7 pairs of submetacentric chromosomes, Spermatogonial metaphase chromosomes range in length from 4.10 ${\mu}{\textrm}{m}$ for the largest pair to 2.20 ${\mu}{\textrm}{m}$ for the smallest pair.

• Parasites, Hosts and Diseases
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• v.37 no.1
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• pp.51-53
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• 1999

A 54-year-old male farmer residing in Chunchon, Korea. complaining of blood tinged discharge and tinnitus in the left ear for two days. was examined in August 16, 1996. Otoscopic examination revealed live maggots from the ear canal. The patient did not complain of any symptoms after removal of maggots. Five maggots recovered were identified as the third stage larvae of Lucilia sericata (Diptera: Calliphoridae). This is the first record of aural myiasis in Korea.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.282-283
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• 2000

급속한 경제 발전과 인구증가, 일회용품의 증가 둥 사회구조가 대량생산, 대량소비 형태로 변화되면서 폐기물의 처리가 새로운 환경문제로 대두되었다. 도시 생활폐기물의 대부분이 매립 처리되고 있지만, 환경부에서는 매립처리의 비율을 줄이고 2001년까지 소각처리 비율을 25%로 늘릴 계획이다. 1997년에는 도시 생활 폐기물의 63.9%가 매립 처리되고 7.1%는 소각 처리되었으며, 29.0%가 재활용되었다(환경부, 1998). 한편 1995년부터는 쓰레기 종량제의 도입으로 도시쓰레기의 27%가 줄어들었고 재활용되는 쓰레기의 양이 35% 정도 늘어났다. (중략)