• 한국사회정책
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• v.24 no.4
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• pp.89-112
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• 2017

Because of low amounts of pension benefit, the Basic Pension of Korea has played a very limited role in reducing the high poverty rates of the elderly. Based on an empirical analysis of the poverty alleviation effect of alternative pension amounts, this paper shows that although the higher basic pension amounts help to reduce the absolute poverty rate of the elderly, it cannot significantly reduce the relative poverty rates. Authors contends that the main objective of the basic pension should be targeted to combat the absolute poverty level. This paper also argues that in order to reduce the relative poverty level of the elderly, the benefit level of National Pension should also be increased.

• The Korean Journal of Applied Statistics
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• v.22 no.2
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• pp.375-385
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• 2009

For 2007 Korea presidential election, most polls by telephone surveys indicated Lee Myung-Bak led the second runner-up Jung Dong-Young by certain margin. The margin between two candidates can be estimated accurately by averaging individual poll results, provided there exists no systematic bias in telephone surveys. Most Korean telephone surveys via telephone directory are based on quota samples, with the region, the gender and the age-band as quota variables. Thus the surveys may result in certain systematic bias due to unbalanced factors inherent in quota sampling. The aim of this study is to answer the following questions by the analytic methods adopted in Huh et al. (2004): Question 1. Wasn't there systematic bias in estimates of support rates. Question 2. If yes, what was the source of the bias? To answer the questions, we collected eighteen surveys administered during the election campaign period and applied the iterated proportional weighting (the rim weighting) to the last eleven surveys to obtain the balance in five factors - region, gender, age, occupation and education level. We found that the support rate of Lee Myung-Bak was over-estimated consistently by 1.4%P and that of Jung Dong-Young was underestimated by 0.6%P, resulting in the over-estimation of the margin by 2.0%P. By investigating the Lee Myung-Bak bias with logistic regression models, we conclude that it originated from the under-representation of less educated class and/or the over-representation of house wives in telephone samples.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.5
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• pp.535-541
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• 1996

A seed pelleting technique was developed for easy handling of small tobacco seeds (variety, NC82) and for direct seeding in temperary planting bed or in field. The mixture of pelleting material, binder and seeds were moulded in cylindrical holes sized 2 mm diameter and 2 mm height in a plastic plate. Bentonite and cellulose powder were good materials to make pellets with CMC as binder, and bentonite formed the hardest pelleted seeds among the materials. The number of the pelleted seeds made with the same weight of the materials was different with materials used and the number of seeds contained in a pelleted seed could be controlled by mixture ratio of materials and seeds. The seedless pellets ranged 6.9 to 16.0% at the ratio of pelleting material and seed for 2~3 seeds in a pellet. The moisture absorption rate at 100% RH and $25^{\circ}C$ was greater in the order of clay < bentonite < cellulose. Germination rates of pelleted seeds with bentonite and cellulose were similar to that of usual seed, but it was significantly lower with clay pelleted seeds.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.105-114
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• 2007

Large span spaces have been widely used for various purposes including sports events in other countries. Due to increasing demands on multi-purpose use of such spaces, recently built large span sport facilities such dome stadiums have been required to accommodate sport events as well as performing events. Also, retractable ceilings and/or walls were generally adopted in those spaces for providing various event conditions. It seems obvious that the openings between diffuse fields and free field may cause difficulties in the acoustic design of such spaces In the present work, the acoustic characteristics of non-diffuse field has been investigated using 1/10 acoustic scale models. It was found that RTs at low- and mid-frequencies decayed faster than those at high-frequencies as the percentage of opening area increased. The decay rate of RTs at high frequencies were not influenced by increasing the area of an opening. Also high dependence of EDT on the percentage of opening area was observed at all frequency range. D50 was not improved by increasing the area of an opening up to 12.5% and then sharply increased. The application of Schroeder integration to evaluate the reverberation charateristics of coupled spaces may not be proper, since non-exponential decay process with double or triple decays of those spaces can not be properly defined. EDT seems more appropriate to predict reverberation at the early acoustic design stage of acoustically coupled spaces.

• Applied Chemistry for Engineering
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• v.4 no.3
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• pp.474-481
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• 1993

The infinite dilution activity coefficients(${\gamma}{\infty}$) of nonpolar and polar solutes have been determined in different solvents at temperature between 60 and $100^{\circ}C$ by using gas chromatography. The $ln{\gamma}{\infty}$ values of nonpolar solutes(alkanes, cyclohexane, benzene, toluene and $CCl_4$) were linearly increased as 1/T in the nonpolar solvent (n-octadecane) and the polar solvent(n-hexadecyl alcohol) systems and the $ln{\gamma}{\infty}$ values at the constant temperature were increased with the number of carbon atoms of solute molecule. For the polar solutes(alcohols, esters and ketones) and the weak polar solvent(di-2-ethyl adiphate and di-2-ethylhexyl sebacate) systems, the relations of $ln{\gamma}{\infty}$ vs. 1/T were found to be curved with increased slope, and the $ln{\gamma}{\infty}$ values at constant temperature were linearly diminished as increasing the number of carbon atoms of solute molecule. For the polar solutes(alcohols, esters and ketones) and the strong polar solvents(triphenyl phosphate and tricresyl phosphate)systems, the relations of $ln{\gamma}{\infty}$ vs. 1/T were found to be curved with increased slope but $ln{\gamma}{\infty}$ values at constant temperature were linearly increased as increasing the number of carbon atoms of solute molecule.

• The Korean Journal of Applied Statistics
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• v.27 no.1
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• pp.21-30
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• 2014

Ordinary survival analysis cannot be applied when a significant fraction of patients may be cured. A cure rate model is the combination of cure fraction and survival model and can be applied to several types of cancer. In this article, the cure rate model is considered in the interval censored data with a cluster effect. A shared frailty model is introduced to characterize the cluster effect and an EM algorithm is used to estimate parameters. A simulation study is done to evaluate the performance of estimates. The proposed approach is applied to the smoking cessation study in which the event of interest is a smoking relapse. Several covariates (including intensive care) are evaluated to be effective for both the occurrence of relapse and the smoke quitting duration.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.1
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• pp.57-70
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• 2017

In this study, we investigated the wear measurement methods for slurry pipe applied in the field of mining and oil sand industry and theoretical equations related to the prediction of wear in slurry pipe through literature review. Average daily wear rate and wear rate per excavated distance were determined from slurry discharge pipe thickness measurement data periodically measured at the actual slurry shield TBM site in Singapore. The wear rate of slurry pipe for Bukit Timah Granite was obtained. The wear rates for G (V) grade and mixed zone were 1.5 times higher than that of G (I) to G (IV) grade. Slurry pipe wear rate tends to increase in proportion to the slurry discharge velocity. The optimal slurry pipe replacement or rotation frequency can be estimated through the selection of the pipe wear rate considering geological condition and the reasonable pipe management thickness.

• Journal of Mushroom
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• v.4 no.1
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• pp.39-42
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• 2006

Cauliflower mushroom(Sparassis crispa) contains much amount of ${\beta}$-glucan, which make lots of farmer want to cultivate the mushroom. Since a practical cultivation method is not provided yet, the mushroom is considered as a difficult crop to deal with. In this study, we tried to develope a simple method to cultivate the mushroom by use of coniferous sawdust-based medium with wheat flour and molasses. There was no significant differences between the sawdust spawn and the liquid spawn for the mycelial growth of the mushroom. The cold shock in $4^{\circ}C$ for a day was thought to be the best way to seduce primordium formation. The sawdust medium of Pseudotsuga menziesii mixed with wheat flour, corn chip, cottonseed meal and 10% molasses was showed the best yield with 41% followed by that of Larix leptolepis mixed with the same additives with 37% of yield. There was good relations between the fruit-body production and the weight loss of the sawdust substrate.

• Journal of the Korean Ceramic Society
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• v.13 no.1
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• pp.11-19
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• 1976

This study was focused on the improvement of production techniques of small crucibles in relation with the appropriate selection of raw materials, various batch compositions and physical and chemical characteristics of the crucibles. Various tests gave the optimum batch composition for the carbon bond graphite cructble as follows: Pyontaek graphite flake (refractory aggregate) : 40Part Silicon carbide: 15Part Tar pitch (binder) : 11Part Inorganic additives (to improve the oxidation resistance) : 15 Part Cryolite : 3 Part Ferro manganese : 2 Part Ferrosilicon : 25 Part Crucibles pressed with 400kg/$\textrm{cm}^2$ at 12$0^{\circ}C$. and fired in reducing atmosphere at 120$0^{\circ}C$ brought the most favorable results as follows: Bulk density : 2.31 Apparent density : 2.58 Porosity : 15.2% Oxidation loss at 1, 50$0^{\circ}C$. for 3 hrs : below 3.77% Water absorption : 6.01% Compressive strength : 438kg/$\textrm{cm}^2$ Tensile strength : 256kg/$\textrm{cm}^2$.

• Journal of Korea Multimedia Society
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• v.5 no.2
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• pp.158-166
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• 2002

In this paper, we proposed a contour shape description method which use the CFR(contour fluctuation ratio) feature. The CFR is the ratio of the line length to the curve length of a contour segment. The line length means the distance of two end points on a contour segment, and the curve length means the sum of distance of all adjacent two points on a contour segment. We should acquire rotation and scale invariant contour segments because each CFR is computed from contour segments. By using the interleaved contour segment of which length is proportion to the entire contour length and which is generated from all the points on contour, we could acquire rotation and scale invariant contour segments. The CFR can describes the local or global feature of contour shape according to the unit length of contour segment. Therefore we describe the shape of objects with the feature vector which represents the distribution of CFRs, and calculate the similarity by comparing the feature vector of corresponding unit length segments. We implemented the proposed method and experimented with rotated and scaled 165 fish images of fifteen types. The experimental result shows that the proposed method is not only invariant to rotation and scale but also superior to NCCH and TRP method in the clustering power.