• Journal of Ecology and Environment
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• v.29 no.2
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• pp.85-103
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• 2006

An investigation of fauna and community of insects in Gotjawal Terrain, Jeju-do, had been conducted with a way of black light trap from July to September, 2005. The investigated insects were classified into 217 species, 75 families, and 11 orders respectively. Coleoptera that occupied 55.3 percent among them and was consisted of 120 species was the richest group and Hemiptera followed it. The density of Physopelta gutta was highest but Physopelta cincticollis was overall the dominant species in all sampling areas. The species diversity index was highest at Jocheon-Hamdeog Gotjawal in Jeju-do, while it was lowest in Gujwa-Sungsan Gotjawal. Clustering analysis revealed that the insect communities of four localities were grouped in only one cluster. Included in the species unreported in Jeju Island were Menida musiva and Pentatoma japonica in Hemiptera, Philonthus wuesthoffi in Coleoptera, and Phanerotoma flava in Hymenoptera.

• Wind and Structures
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• v.27 no.3
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• pp.175-186
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• 2018

With the continuous increase of span lengths, modern bridges are becoming much more flexible and more prone to flutter under wind excitations. A reasonable probabilistic flutter analysis of long-span bridges involving random and uncertain variables may have to be taken into consideration. This paper presents a method for estimating the reliability index and failure probability due to flutter, which considers the very important variables including the extreme wind velocity at bridge site, damping ratio, mathematical modeling, and flutter derivatives. The Aizhai Bridge in China is selected as an example to demonstrate the numerical procedure for the flutter reliability analysis. In the presented method, the joint probability density function of wind speed and wind direction at the deck level of the bridge is first established. Then, based on the fundamental theories of structural reliability, the reliability index and failure probability due to flutter of the Aizhai Bridge is investigated by applying the Monte Carlo method and the first order reliability method (FORM). The probabilistic flutter analysis can provide a guideline in the design of long-span bridges and the results show that the structural damping and flutter derivatives have significant effects on the flutter reliability, more accurate and reliable data of which is needed.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.100-100
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• 2003

The purpose of this study is to reveals spatial relationships between landslides and geospatial data set, map the landslide susceptibility using the relationships and verify the landslide susceptibility using the landslide occurrence data in Bosun area in 1998. Landslide locations were detected from aerial photography and field survey and topography, soil, forest, and land use data sets were constructed as a spatial database using GIS. As the landslide occurrence factors, slope, aspect, curvature and type of topography, texture, material, drainage and effective thickness of soil, type, age, diameter and density of wood and land use were used. Is extract the relationship between landslides and geospatial database, Bayesian probability methods, likelihood ratio and weight of evidence, were applied and the ratio and contrast value that is W$\^$＋/- W$\^$-/ were calculated. The landslide susceptibility index was calculated by summation of the likelihood ratio and contrast value and the landslide susceptibility maps were generated using the index. As a result, it is expected that spatial relationships between landslides and geospatial database is helpful to explain the characteristics of landslide and the landslide susceptibility map is used to reduce associated hazards, and to plan land use and construction.

• Journal of the Korean Chemical Society
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• v.56 no.4
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• pp.424-430
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• 2012

Densities, viscosities, refractive indices and speed of sounds of the binary mixtures of Acetophenone with Ethylchloroacetate were measured over the entire mole fractions at (303.15, 313.15 and 323.15) K. From these experimental results, excess molar volume $V^E$, viscosity deviation ${\Delta}{\eta}$, refractive index deviation ${\Delta}n_D$, deviations in speed of sound ${\Delta}u$, deviations in isentropic compressibility ${\Delta}k_s$ and excess intermolecular free length ${\Delta}L_f$ were calculated. The viscosity data have been correlated with the equations of Grunberg and Nissan, Hind et al., Tamura and Kurata, Katti and Chaudri, Sedgwick, Krishnan-Laddha and McAllister. The thermo physical properties under study were fit to the Jouyban-Acree model. The excess values were correlated using Redlich-Kister polynomial equation to obtain their coefficients and standard deviations. It was found that in all cases, the data obtained fitted with the values correlated by the corresponding models very well. The results are interpreted in terms of molecular interactions occurring in the solution.

• Journal of the East Asian Society of Dietary Life
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• v.7 no.1
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• pp.71-86
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• 1997

The 297 middle school girls in Inchon were devided into three groups according to body mass index(BMI), the under weight group, the normal weight group and obese group to find out relationship between their food habits, food preference, and obesity. The average height and weight are 159.40cm, 67.02kg for obese group, 158.17cm, 39.11kg for under weight group, 156.93cm, 53.78kg for normal weight group. Obese group feels that they are healthy and fat, and their parents are fat also than the other groups. Obese group took more exercise. Total Food habits scores of obese group were lower than the other two groups. In terms of supper, bedtime-smack, unbalanced diet, balanced intake of five basic food groups obese group had lower scores. Especially, intake of carbohydrate, protein, milk group were irregular. There is no significant different in size of meal, overeating eating speed. The preferences of fast food, instant food, high caloric density food were lower in obese group than in the other two groups. The mother of obese group prepared meals according to food composition and prepared little snakes.

• Journal of Preventive Medicine and Public Health
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• v.47 no.6
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• pp.289-297
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• 2014

Objectives: This community-based cohort study was performed to investigate the incidence of and factors related to self-reported fragility fractures among middle-aged and elderly women living in rural Korea. Methods: The osteoporosis cohort recruited 430 women 40 to 69 years old in 1999, and 396 of these women were followed over 11 years. In 1999, questionnaires from all participants assessed general characteristics, medical history, lifestyle, menstrual and reproductive characteristics, and bone mineral density. In 2010, self-reported fractures and the date, site, and cause of these fractures were recorded. Cox proportional hazards models were used to calculate hazard ratios (HRs). Results: Seventy-six participants among 3949.7 person-years experienced fragility fractures during the 11-year follow-up. The incidence of fragility fractures was 1924.2 per 100 000 person-years (95% confidence interval [CI], 1491.6 to 2356.8). In the multivariate model, low body mass index (HR, 2.66; 95% CI, 1.13 to 6.24), a parental history of osteoporosis (HR, 2.03; 95% CI, 1.18 to 3.49), and postmenopausal status (HR, 3.50; 95% CI, 1.05 to 11.67) were significantly related to fragility fracture. Conclusions: Fracture prevention programs are needed among postmenopausal, rural, Korean women with a low body mass index and parental history of osteoporosis Korea.

• The Bulletin of The Korean Astronomical Society
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• v.43 no.1
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• pp.56.1-56.1
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• 2018

Tidal disruption events (TDEs) provide evidence for quiescent supermassive black holes (SMBHs) in the centers of inactive galaxies. TDEs occur when a star on a parabolic orbit approaches close enough to a SMBH to be disrupted by the tidal force of the SMBH. The subsequent super-Eddington accretion of stellar debris falling back to the SMBH produces a characteristic flare lasting several months. The theoretically expected bolometric light curve decays with time as proportional to $t^{-5/3}$. However, the light curves observed in most of the optical-UV TDEs deviate from the $t^{-5/3}$ decay rate especially at early time, while the light curves of some soft-X-ray TDEs are overall in good agreement with the $t^{-5/3}$ law. Therefore, it is required to construct the theoretical model for explaining these light curve variations consistently. In this paper, we revisit the mass fallback rates analytically and semi-analytically by taking account of the structure of the star, which is simply modeled by the polytrope. We find the relation between a polytropic index and the power law index of the mass fallback rate. We also discuss whether and how the decay curves, which we derived, fit the observed ones.

• Journal of agricultural medicine and community health
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• v.18 no.2
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• pp.161-171
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• 1993

Mycoplasma pneumoniae(M. pneumoniae) is a primary pathogene of the respiratory tract in children. Most studies of such pneumonia involve a group of admitted patients in hospital, usually with major medical illness. We retrospectively studied the epidemiologic and clinical feature of 105 patients with serologically proven M. pneumoigic pneumonia treated at Gwang-Yang Hospital during a epidemic period of Jun. 1993 to Dec. 1993. All cases of pneumonia developed in this period were also reviewed and compared with serologically proven group. The results were as follows. 1. There were 63 males and 42 females, and the male /female ratio was 1.5 : 1. 2. More than half(57%) of cases belonged to 5-9 years of age group, and mean age was 6.5 years old. 3. Mean age was steadily decreased as prevalence of mycoplasmal pneumonia had been subsided. 4. The date of index case was June 26th, and that of median case was 3 months after the index case. 5. A major determinant of the outbreak seemed to be the population density rather than the population size. 6. Recurrence and serious complication were not observed in this period. 7. All cases of pneumonia developed in this period might be attributed to M. pnemoniae. These epidemiologic and clinical characteristics would contribute to the prevention and diagnosis of mycoplasmal pneumonia.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.2
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• pp.99-106
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• 2006

In this paper, the new method that estimates a sensing ability of smart sensor will be proposed. A study is estimation method that evaluates sensing ability about smart sensor respectively. According to acceleration(g) and displacement changing, we estimated sensing ability of smart sensor using SAI(Sensing Ability Index) method respectively. Smart sensors was made fer experiment. The types of smart sensor are two types(hard and soft smart sensor). Smart sensors developed for recognition of material. Experiment and analysis are executed for estimate the SAI method. In develop a smart sensor, the SAI method will be useful for finding optical design condition of smart sensor that can sense a material. And then dynamic characteristics of smart sensors(frequency changing, acceleration changing, critical point, etc.) are evaluated respectively through new method(SAI) that use the power spectrum density. Dynamic characteristic of sensor is evaluated with SAI method relatively. We can use the SAI for finding critical point of smart sensor, too.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.563-566
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• 2002

We investigated to decrease the leakage current of SiNx film by employing $N_2$ plasma treatment. The insulator layers were prepared by two step process; the $N_2$ plasma treatment and then PECVD SiNx deposition with $SiH_4$, $N_2$ gases. To prove the influence of the $N_2$ plasma treatment, the Si substrate was exposed to the plasma, which was generated in Ne gas ambient. Without plasma treatment SiNx film grow at the rate of 7. 03 nm/min, has a refractive index n = 1.77 and hydrogen content of $2.16{\times}10^{22}cm^{-3}$ for $N_2/SiH_4$ gas flow ratio of 20. The obtained films were analyzed in terms of deposition rates, refractive index, hydrogen concentration, and electrical properties. By employing $N_2$ plasma treatment, interface traps such as mobile charges and injected charges were removed, hysteresis of capacitance-voltage (C-V) disappeared. We observed plasma treated sample were decreased the leakage current density reduces by 2 orders with respect to the sample having no plasma treatment.