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A Bayesian uncertainty analysis for nonignorable nonresponse in two-way contingency table

  • Woo, Namkyo;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.6
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    • pp.1547-1555
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    • 2015
  • We study the problem of nonignorable nonresponse in a two-way contingency table and there may be one or two missing categories. We describe a nonignorable nonresponse model for the analysis of two-way categorical table. One approach to analyze these data is to construct several tables (one complete and the others incomplete). There are nonidentifiable parameters in incomplete tables. We describe a hierarchical Bayesian model to analyze two-way categorical data. We use a nonignorable nonresponse model with Bayesian uncertainty analysis by placing priors in nonidentifiable parameters instead of a sensitivity analysis for nonidentifiable parameters. To reduce the effects of nonidentifiable parameters, we project the parameters to a lower dimensional space and we allow the reduced set of parameters to share a common distribution. We use the griddy Gibbs sampler to fit our models and compute DIC and BPP for model diagnostics. We illustrate our method using data from NHANES III data to obtain the finite population proportions.

Development of Think-aloud Program for Acquiring Abstraction Concept

  • Kim, Ji-Yun;Lee, Tae-Wuk
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.12
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    • pp.227-234
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    • 2016
  • In this paper, we propose a think-aloud program for acquiring abstraction concept. Think-aloud is a technique, which is good for teaching higher-order thinking skills to learner. We intend to propose a program for teaching abstraction concept to learners directly, as software education is being reinforced in the current education policy. For the study, we develop a program depending on ADDIE model. According to these steps, we analyzed related works such as computational thinking, think-aloud technique, and direct instructional model. After that, we split and structuralized the learning tasks for achieving a goal. And then, we constructed steps for the instruction and detailed contents of the program. We did a survey for verification to nine experts and we corrected the program according to it.

Bayesian estimation for finite population proportions in multinomial data

  • Kwak, Sang-Gyu;Kim, Dal-Ho
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.3
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    • pp.587-593
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    • 2012
  • We study Bayesian estimates for finite population proportions in multinomial problems. To do this, we consider a three-stage hierarchical Bayesian model. For prior, we use Dirichlet density to model each cell probability in each cluster. Our method does not require complicated computation such as Metropolis-Hastings algorithm to draw samples from each density of parameters. We draw samples using Gibbs sampler with grid method. We apply this algorithm to a couple of simulation data under three scenarios and we estimate the finite population proportions using two kinds of approaches We compare results with the point estimates of finite population proportions and their standard deviations. Finally, we check the consistency of computation using differen samples drawn from distinct iterates.

Filter Design for Fault Location Detection on Underground Power Cable (지중송전케이블 고장신호 처리를 위한 필터 설계)

  • Lee, Jae-Duck;Ryoo, Hee-Suk;Choi, Sang-Bong;Nam, Kee-Young;Jeong, Seong-Hwan;Kim, Dae-Kyeong
    • Proceedings of the KIEE Conference
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    • 2003.11a
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    • pp.361-363
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    • 2003
  • To reduce the effect of fault on underground power cable, we need exact and fast fault location detection technique. In this thesis, we describe on filter design technique that can be applied to on-line fault defection technique. To design fitter for fault location defection on Power cable, we should analysis fault signal. So we designed test bed for fault generation and measured fault signals for analysis. Through the analysis of signals, we found that ANC filter can be applied to separate fault signals and we designed a ANC filter. We tested on the designed filter through computer simulation, and we describe its results in this paper.

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Test procedures for the mean and variance simultaneously under normality

  • Park, Hyo-Il
    • Communications for Statistical Applications and Methods
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    • v.23 no.6
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    • pp.563-574
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    • 2016
  • In this study, we propose several simultaneous tests to detect the difference between means and variances for the two-sample problem when the underlying distribution is normal. For this, we apply the likelihood ratio principle and propose a likelihood ratio test. We then consider a union-intersection test after identifying the likelihood statistic, a product of two individual likelihood statistics, to test the individual sub-null hypotheses. By noting that the union-intersection test can be considered a simultaneous test with combination function, also we propose simultaneous tests with combination functions to combine individual tests for each sub-null hypothesis. We apply the permutation principle to obtain the null distributions. We then provide an example to illustrate our proposed procedure and compare the efficiency among the proposed tests through a simulation study. We discuss some interesting features related to the simultaneous test as concluding remarks. Finally we show the expression of the likelihood ratio statistic with a product of two individual likelihood ratio statistics.

JORDAN 𝒢n-DERIVATIONS ON PATH ALGEBRAS

  • Adrabi, Abderrahim;Bennis, Driss;Fahid, Brahim
    • Communications of the Korean Mathematical Society
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    • v.37 no.4
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    • pp.957-967
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    • 2022
  • Recently, Brešar's Jordan {g, h}-derivations have been investigated on triangular algebras. As a first aim of this paper, we extend this study to an interesting general context. Namely, we introduce the notion of Jordan 𝒢n-derivations, with n ≥ 2, which is a natural generalization of Jordan {g, h}-derivations. Then, we study this notion on path algebras. We prove that, when n > 2, every Jordan 𝒢n-derivation on a path algebra is a {g, h}-derivation. However, when n = 2, we give an example showing that this implication does not hold true in general. So, we characterize when it holds. As a second aim, we give a positive answer to a variant of Lvov-Kaplansky conjecture on path algebras. Namely, we show that the set of values of a multi-linear polynomial on a path algebra KE is either {0}, KE or the space spanned by paths of a length greater than or equal to 1.

Study of the offects of moxibustion at the Sin-Soo and We-soo on HgCl2-Induced Acute Renal Failure in Rats (애구(艾灸)의 생체반응(生體反應)이 신부전(腎不全)에 미치는 영향(影響))

  • Hur, Duk-Soo;Park, In-Kyu;Lim, Jong-Kook
    • The Journal of Dong Guk Oriental Medicine
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    • v.1
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    • pp.237-249
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    • 1992
  • In order to study tile effects of moxibustion on renal failure induced by $HgCl_2$ in rats aminal experiments were carry out. The moxibustion was treat into Sin-soo locus(VII23), We-soo locus(VII21) and Sin-soo + We-soo loci these loci were correspond to human body. Experimental group were divided into 4 groups : lontrol group, moxibustion groups treat on Sin-Soo and We-Soo, Sin-Soo + We-Soo group. The obtained results were as follows : 1. The concentration of serum sodium were inreased in all the groups, compared with those of the control group. Sin-Soo, We-Soo, Sin-Soo + We-Soo loci showed increased on the 1st and 3rd days. All three experimental groups showed a significant increased on 3rd day. 2. The concentration of serum potassium were decreased in all the group, compared with those of the control group. Sin-Soo, We-Soo showed a significant decrease on 3rd day. Sin-Soo + We-Soo showed a little decrease but do not significant decrease. 3. The levels of serum total protein were increased in all the group, compare with those of the control group. Sin-Soo, We-Soo show a significant increased or 3rd day. Sin-Soo + We-Soo do not showed a significant increased. 4. The levels of serum albumin were decreased in all the groups, compared with those of the control group. Sin-Soo, Sin-Soo + We-Soo showed a significant decrease on 3rd day. We-Soo does not showed a significant decrease. 5. The concentration of serum blood urea nitrogen were decreased in all the groups, compared with those of the control group. Sin-Soo, We-Soo, Sin-Soo + We-Soo showed a significant decrease on 3rd day. 6. The levels of serum alkaline phosphatase were decreased in all the group, compared with those of the control groups. Sin-Soo, We-Soo showed a significant decrease on 3rd day Sin-Soo + We-Soo not a significant decrease. In conclusion, the result of this study seemed to effect on the treatment for renal failure induced by $HgCl_2$.

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A Study on the Definitions Presented in School Mathematics (학교수학 교과서에서 사용하는 정의에 관한 연구)

  • 우정호;조영미
    • Journal of Educational Research in Mathematics
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    • v.11 no.2
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    • pp.363-384
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    • 2001
  • The purpose of this thesis is, through analysing the characteristics of the definitions in Korean school mathematics textbooks, to explore the levels of them and to make suggestions for definition - teaching as a mathematising activity, Definitions used in academic mathematics are rigorous. But they should be transformed into various types, which are presented in school mathematics textbooks, with didactical purposes. In this thesis we investigated such types of transformation. With the result of this investigation we tried to identify the levels of the definitions in school mathematics textbooks. And in school mathematics textbooks there are definitions which carry out special functions in mathematical contexts or situations. We can say that we understand those definitions, only if we also understand the functions of definitions in those contexts or situations. In this thesis we investigated the cases in school mathematics textbooks, when such functions of definition are accompanied. With the result of this investigation we tried to make suggestions for definition-teaching as an intellectual activity. To begin with we considered definition from two aspects, methods of definition and functions of definition. We tried to construct, with consideration about methods of definition, frame for analysing the types of the definitions in school mathematics and search for a method for definition-teaching through mathematization. Methods of definition are classified as connotative method, denotative method, and synonymous method. Especially we identified that connotative method contains logical definition, genetic definition, relational definition, operational definition, and axiomatic definition. Functions of definition are classified as, description-function, stipulation-function, discrimination-function, analysis-function, demonstration-function, improvement-function. With these analyses we made a frame for investigating the characteristics of the definitions in school mathematics textbooks. With this frame we identified concrete types of transformations of methods of definition. We tried to analyse this result with van Hieles' theory about levels of geometry learning and the mathematical language levels described by Freudenthal, and identify the levels of definitions in school mathematics. We showed the levels of definitions in the geometry area of the Korean school mathematics. And as a result of analysing functions of definition we found that functions of definition appear more often in geometry than in algebra or analysis and that improvement-function, demonstration-function appear regularly after demonstrative geometry while other functions appear before demonstrative geometry. Also, we found that generally speaking, the functions of definition are not explained adequately in school mathematics textbooks. So it is required that the textbook authors should be careful not to miss an opportunity for the functional understanding. And the mathematics teachers should be aware of the functions of definitions. As mentioned above, in this thesis we analysed definitions in school mathematics, identified various types of didactical transformations of definitions, and presented a basis for future researches on definition teaching in school mathematics.

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Measures to Generalize the Effect of u-Iearning (유러닝 효과성의 일반화 방안)

  • Ahn, Seong-Hun;Jeong, Young-Sik
    • The Journal of the Korea Contents Association
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    • v.9 no.7
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    • pp.379-389
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    • 2009
  • In this paper, we analyzed the effect of u-learning model school which have been in forced by the Ministry of Education. We suggested a plan which we generalized the effects of u-learning. To analyzed the effects of u-learning, first of all, we set up indexes of u-learning effect - satisfaction measurement, efficacy measurement, the scholastic achievements, possibility of generalization. After we reanalyzed reports of model school and papers of u-learning, we looked for suggestions of the effects u-learning. We draw up a plan which we generalized the effects of u-learning according to suggestions. We devide a plan by 3 steps - introduction step, diffusion step, fixation step and every step by 4 field - policy of u-learning, teaching & learning, quality control, technology. Because we suggested a concrete plan which we generalized the effects of u-learning, we expect to use usefully our plan at school in the future.

Effects of Danggi-Jakyak-San on Antiplatelet and Antihemolysis Activity of in Human blood

  • Sa, Eun-Ho;Son, Soo-Gon;Park, Won-Hwan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.20 no.2
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    • pp.460-466
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    • 2006
  • We wondered whether the mechanisms of antiplatelet aggregation of DJS-WE were through multiple pathways. Danggijakyak-san(DJS) consisting of 6 herbes of Paeoniae Radix, Poria Cocos, Angelicae Sinensis Radix, Cnidii Rhizoma, Atractylodis Macrocephalae Rhizoma and Alismatis Rhizoma, is a crude mixture of a commonly used Korean herbal medicine. The water extract (DJS-WE) of DJS has been known to have an anti-platelet aggregation activity. We have reported that DJS-WE inhibited ADP-induced aggregation as well as arachidonic acid-induced aggregation of human platelet. Clinical studies on the cardiovascular effects of DJS-WE have been done in Korea. The DJS has been used as a remedy for gastrointestinal disorders (abdominal pain, dysentery), headache, amenorrhea, and postpartum hemorrhage. It has also been claimed to have a remarkable central stimulant effect, a transient hypertensive effect, and positive inotropic and chronotropic effects. In this paper, we evaluated the possible mechanisms of the antiplatelet activity of DJS-WE using human platelets. On the other hand, the role of DJS-ethanol extract on the inhibition of platelet aggregation and hemolytic effect have not yet been investigated in detail. We also used the method of activated partial thromboplastin times (APTT) for the first time to study the inhibition on platelet aggregation activity of DJS-ethanol extract. The effect of DJS-WE on hemolysis was also investigated. DJS-WE showed a high hemolysis ability on human blood.