• Communications for Statistical Applications and Methods
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• v.10 no.2
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• pp.553-566
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• 2003

In many cases, the measurement error variances may be functions of the unknown true values or related covariates. This paper considers design-based estimators of the parameters of these variance functions based on the within-unit sample variances. This paper devotes to: (1) define an error scale factor $\delta$; (2) develop estimators of the parameters of the linear measurement error variance function of the true values under large-sample and small-error conditions; (3) use propensity methods to adjust survey weights to account for possible selection effects at the replicate level. The proposed methods are applied to medical examination data from the U.S. Third National Health and Nutrition Examination Survey (NHANES III).

• The Journal of Asian Finance, Economics and Business
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• v.8 no.4
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• pp.171-180
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• 2021

The purpose of this paper is to estimate the impact of credit rationing on the amount of trade credit used by farmers in Vietnam. This study employs a survey data collected through direct interviews with heads of 1,065 rice households randomly selected out of provinces and city in the Mekong River Delta (MRD). In each province or city, the village with the largest area of land devoted to rice production from the district with the largest area of land devoted to rice production was picked up for survey. In each village, 200 rice farmers were randomly chosen for interview. Based on a probit model and a semi-parametric propensity score matching (PSM) estimator while controlling socio-demographic traits of rice farmers, the estimated results show that non-credit rationed farmers use less trade credit to finance production compared to their credit rationed counterparts. Moreover, the amount of trade credit used by farmers decreases as the degree of credit rationing drops. This paper provides evidence of the substitutive relationship between bank credit and trade credit. It also implicitly suggests that banks can drive trade creditors out of the market if they manage to solve the problem of information asymmetry and transaction cost.

• Communications for Statistical Applications and Methods
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• v.29 no.2
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• pp.177-191
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• 2022

This paper addresses the use of machine learning methods for causal estimation of treatment effects from observational data. Even though conducting randomized experimental trials is a gold standard to reveal potential causal relationships, observational study is another rich source for investigation of exposure effects, for example, in the research of comparative effectiveness and safety of treatments, where the causal effect can be identified if covariates contain all confounding variables. In this context, statistical regression models for the expected outcome and the probability of treatment are often imposed, which can be combined in a clever way to yield more efficient and robust causal estimators. Recently, targeted maximum likelihood estimation and causal random forest is proposed and extensively studied for the use of data-adaptive regression in estimation of causal inference parameters. Machine learning methods are a natural choice in these settings to improve the quality of the final estimate of the treatment effect. We explore how we can adapt the design and training of several machine learning algorithms for causal inference and study their finite-sample performance through simulation experiments under various scenarios. Application to the percutaneous coronary intervention (PCI) data shows that these adaptations can improve simple linear regression-based methods.

• Journal of Sericultural and Entomological Science
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• v.27 no.2
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• pp.54-63
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• 1985

This studies has been carried out how to effect on electrostafic propensity of synthetic fabrics by coating with 0.5% acrylic polymer solution which was previously developed by the author to improve anticrease nature of silk. The work conditions are: (A) Applied synthetic polymer was acrylic polymer 525, developed by the author. (B) Electrostatic voltage for various fabrics were carried out by Korea standard abrasion partner with Korea standard (KS K 0905) cotton, nylon, polyester and the self sample fabric. (C) Applied fabrics for the investigations were carried out by using abrasion partner with Korea standard (KS K 0905) cotton, nylon, polyester and the self sample fabric. (D) Electrostatic propensity investigations were carried out by use of sample as silk, nylon, polyester and acrylic fabrics, seperating before finish or after finish. (E) Washing after the finish or the original fabric was carried out by Korea standard method, KS K 0465. Through the investigations, he happened to find many interesting matters and the obtained results are as followings. 1. Electrostatic voltage for the finished fabrics increased more than their original silk, nylon, acrylic fabrics except polyester fabric. (See Table 5) 2. Electrostatic voltage for the finished polyester against K.S. polyester decreased remarkably than the original fabric test. 3. In spite of no problem on electrostatic propensity of silk, it showed high electrostatic voltage between the same nature fabric abrasion, because silk is very weak against abrasion and because the test method had been developed to be useful for only synthetic fabrics. 4. Electrostatic voltage increased more in case of abrasion between different nature of fabrics than the same nature of fabrics. 5. Electrostatic voltage of each fabric increased by repeat of wash. 6. Many investigation data were followed with Contact Electrification Series Principle, another word, the farther each other located fabric on the series abrasion was, the higher electrostatic voltage. (See Fig. 6) 7. Such investigation gives warning of use on the mix fiber spinning service as far as concern with electrification. 8. It may also call attention for such increase of electrification in case any finishing of silk textile.

• Journal of Society of Preventive Korean Medicine
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• v.3 no.1
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• pp.157-172
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• 1999

This treatise, after review recent data on Oriental Medical toxicity, gets a conclusion on toxic concept of Oriental Medicine. 1. In the oriental medicine, the concept of toxic character contains propensity which disposition is inclined, and general meaning covered with the effect of a medicine, a side effect, formation of a medicine Besides, the concept diversely is used in the cause of a disease, names, symptoms, how to treat, medicines, prevention name, etc. 2. Every herbal drugs has toxic character. Levels of toxicity are nonexistence(無毒), existence(有毒), a little(小毒), always(常毒), serious(大毒), fatal toxic(劇毒), whose concepts in the Oriental Medicine are divided relative and absolute at the same time. 3. The examples of the fatal events by poisoning up to now are more than 400 cases(in China). 4. The factors of toxicity are the amount used unsuitably, the combination, directions, and interactions between western and oriental medicine, etc. The reduction of toxicity and how to detoxicate is several methods. The toxic science in Oriental Medicine based on the formation of oriental medicine present principles which use herbal drugs safely and availablely, utilizing th dispositions and efficiencies. It has positive, learning spirits which prevent abuse of oriental medicine, and which exactly diagnose and use the herbal drugs in the treatment with absolute toxic medicine. However, I think that scientific, positive experimental research is necessary to setup dose-response relation, be in relative quantity of toxic character, operate on the reactive mechanism exactly.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.253-260
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• 2012

This study were investigated to the factors affecting smart phone applications to avoid display ads. The results of this study are as follows. First, factor analysis, propensity for advertising intrusion was the result of a single factor. Also showed significant effect advertising intrusion ad avoidance tendency. Second, the smartphone motivation for the use of the results of factor analysis, seven factors were, Entertainment, information acquisition, learning/work use, multimedia use, ease of life, time leverage, respectively. Showed low levels of advertising avoidance learning/working synchronous usability and ease high motivation life. Finally a smart phone for involvement that there is no significant difference in advertising intrusion tendency appeared. High involvement group was obtaining information, entertainment, social relationships, and multimedia use, ease of living, time management motivation significantly higher than the low involvement group. The results of this study it is expected that the smartphone application smartphone users to reduce evasion of advertising practitioners to give answers to create display ads advertising.

• Journal of the Korean association of regional geographers
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• v.14 no.4
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• pp.367-381
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• 2008

The purpose of this paper is to analyze the change in the distribution and hierarchical structure of commercial land use. Tools for analyzing the spatial structure are index of concentration, coefficient of localization and location quotient. This research is applied to Daegu, focusing on the period 1985-2003. During the 1985-2003 period, the growth rate of commercial land use volume amounted to 330%, compared with a population growth rate of 118%. The biggest component of commercial land use is the retail sector. As the lodging, medical, transportation-warehouse and entertainment sectors have the propensity for concentration and comprise the specialized commercial areas in the suburbs, the other sectors arc evenly distributed. Jung-gu has functioned as a downtown core in the hierarchical structure of commercial areas. So, in the structure of commercial land use, Daegu has continued to be a single nuclear structure. But, Dongdaegu Station influence area has evolved into the second order center since 2000. This is the sign of change in spatial structure from single-nuclear pattern to multi nuclear pattern.

• Journal of Korean Society of Rural Planning
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• v.19 no.4
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• pp.55-71
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• 2013

This study of the living environment for rural residents to identify the relationship between perception and satisfaction are as. Jeollabukdo rural residents survey and SPSS 18.0 statistical program utilizes improvement of rural environment and living conditions were discussed. The main analysis results are summarized as follows. First, rural residents use the facility convenience and accessibility, economic burden, there was a tendency to recognize the important, good natural environment or their children / relatives for the distance was a low awareness. Second, the location and land a job for men, the women have a higher awareness of the use of public transportation inclination showed less than 50 age group showed higher awareness. Third, the rural living environment of residents' satisfaction with 3.544, and overall satisfaction with village life showed a high propensity men have higher satisfaction than women. Finally, the living environment for the perception and satisfaction with the relationship between residential stability and economic awareness of a higher living environment was found that high satisfaction. These findings further improve the rural environment, improve satisfaction in that you can plan the basis for an effective strategy can be. More sustainable in the future, including the analysis of various parameters in progress by being linked to policy measures that will be provided.

• Transactions of the Korean hydrogen and new energy society
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• v.15 no.1
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• pp.12-22
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• 2004

In order to evaluate the potential of partial hydrocarbon substitution to improve the safety of hydrogen use in general and the performance of internal combustion engines in particular, the outward propagation and development of surface cellular instability of spark-ignited spherical premixed flames of mixtures of hydrogen, hydrocarbon, and air were experimentally studied at NTP (normal temperature and pressure) condition in a constant-pressure combustion chamber. With propane being the substituent, the laminar burning velocities, the Markstein lengths, and the propensity of cell formation were experimentally determined, while the laminar burning velocities and the associated flame thicknesses were computed using a recent kinetic mechanism. Results show substantial reduction of laminar burning velocities with propane substitution, and support the potential of propane as a suppressant of both diffusional-thermal and hydrodynamic cellular instabilities in hydrogen-air flames.

• Journal of the Korean Society of Costume
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• v.23
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• pp.131-150
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• 1994

Knitwears are originated earlier than textiles in human beings life. And then human beings life. And then human beings have been continuously developing as life patterns of human beings are becoming various and society is rapidly changing. Recently , changing life styles of the consumer emphasize the importance of the high quality , individuality , variety , and activity of knitwears. In this study , university women and housewives livings in Seoul have been surveyed in the cause of analyzing of the consumer's actual conditions. And eight brands of th specialized knit enterprises also have been surveyed, though it is imperfect . The purpose of this study lies in giving a help to the rational clothing habits of consumer and presenting some courses for aiming of korean knit industry. I made use of percentage and $x^2$-test for the analysis of the data and analyzed the contents of the question papers.