• East Asian mathematical journal
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• v.30 no.3
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• pp.355-360
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• 2014

Let D be a finite digraph with the vertex set V (D) and the arc set A(D). A function f : $V(D){\rightarrow}\{-1,\;1\}$ defined on the vertices of a digraph D is called a bad function if $f(N^-(v)){\leq}1$ for every v in D. The weight of a bad function is $f(V(D))=\sum\limits_{v{\in}V(D)}f(v)$. The maximum weight of a bad function of D is the the negative decision number ${\beta}_D(D)$ of D. Wang [4] studied several sharp upper bounds of this number for an undirected graph. In this paper, we study sharp upper bounds of the negative decision number ${\beta}_D(D)$ of for a digraph D.

• East Asian mathematical journal
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• v.35 no.1
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• pp.85-90
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• 2019

In this paper, we are interested in the evaluation of special values of the Dedekind zeta function of a totally real number field. In particular, we revisit Siegel method for values of the zeta function of a totally real number field at negative odd integers and explain how this method is applied to the case of non-normal totally real number field. As one of its applications, we give divisibility property for the values in the special case

• Bulletin of the Korean Mathematical Society
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• v.38 no.1
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• pp.55-63
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• 2001

In this paper, we derive a general strong law of large numbers and a general weak law of large number for normed weighted sums of pairwise negative quadrant dependent random variables with the common distribution function.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.4 no.5
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• pp.896-909
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• 2010

IEEE 802.11 medium access control (MAC) employs the distributed coordination function (DCF) as the fundamental medium access function. DCF operates with binary exponential backoff (BEB) in order to avoid frame collisions. However it may waste wireless resources because collisions occur when multiple stations are contending for frame transmissions. In order to solve this problem, a binary negative-exponential backoff (BNEB) algorithm has been proposed that uses the maximum contention window size whenever a collision occurs. However, when the number of contending stations is small, the performance of BNEB is degraded due to the unnecessarily long backoff time. In this paper, we propose the adaptive BNEB (A-BNEB) algorithm to maximize the throughput regardless of the number of contending stations. A-BNEB estimates the number of contending stations and uses this value to adjust the maximum contention window size. Simulation results show that A-BNEB significantly improves the performance of IEEE 802.11 DCF and can maintain a high throughput irrespective of the number of contending stations.

• Journal of Korean Medical Ki-Gong Academy
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• v.20 no.1
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• pp.148-162
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• 2020

Objective : The purpose of this study is not only to examine the negative functions of alcohol, but also to examine the positive functions and look at it with a balanced perspective. Methods : We investigated the number of times the word "酒"(alcohol) appears in 《Hwangjenaegyeong》 and 《Gyeongakjeonseo》. The meaning of alcohol was divided into seven categories. The number of positive and negative functions of alcohol was counted and the ratio was calculated. Results : 1. In the 《Hwangjenaegyeong》, the word alcohol appears 23 times, of which 9 times has positive functions, 10 times has negative functions, and the remaining 4 times does not correspond anywhere. The ratio of positive functions is 39.13% and negative functions 43.48%. 2. In the 《Gyeongakjeonseo》, the word alcohol appears 1,487 times, of which 1,140 times (76.66%) has positive functions, and 327 times (21.99%) has negative functions. Conclusions : 1. In 《Hwangjenaegyeong》, the number of comments about positive and negative functions of alcohol is similar. 2. 《Gyeongakjeonseo》 has commented a lot about the positive functions of alcohol. However, it has more mentions to negative functions of alcohol except for those related to herbs and prescriptions (48 to 64 chapter). 3. It is somewhat unreasonable to judge the emphasis on the positive and negative function of alcohol according to the number of references to alcohol in oriental medicine classics. But in these books, we can find a balanced approach between the two sides, not a one-sided biased view. 4. From a curative point of view, it is desirable to know and to use the positive and negative functions of alcohol, and drink alcohol as appropriate control.

• Journal of Korea Multimedia Society
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• v.23 no.1
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• pp.93-101
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• 2020

Korea, as a leader of Internet and game sector in IT industry, has been playing an important role in increasing its industrial development. This country has won the first place in wireless broadband usage and contributed to Internet game industry development. This means that Korean use smartphones most. It is juveniles that use Internet and smartphones most among Korean who use teenage., the number of the teenagers who overuse smartphones or Internet has surpassed 200,000. The number of the adolescents who spend more time using smartphone and Internet is about 180,000 and the number of the teens who are over-dependent to smartphone having trouble living their lives is over 22,000. The SNS usage rate of the contents that teens are most likely to use has accounted for over 80 percent. Among teens, SNS is being considered as a major means that builds relationship due to smartphone technology and the prevalence of smartphones. However, the use of SNS among youths has two sides; one is positive, the other negative. Not only does SNS have a positive function that it keeps relationship but it also has a negative function that it can lead to smartphone addiction.

• ETRI Journal
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• v.39 no.5
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• pp.621-631
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• 2017

Abnormal samples are usually difficult to obtain in production systems, resulting in imbalanced training sample sets. Namely, the number of positive samples is far less than the number of negative samples. Traditional Support Vector Machine (SVM)-based anomaly detection algorithms perform poorly for highly imbalanced datasets: the learned classification hyperplane skews toward the positive samples, resulting in a high false-negative rate. This article proposes a new imbalanced SVM (termed ImSVM)-based anomaly detection algorithm, which assigns a different weight for each positive support vector in the decision function. ImSVM adjusts the learned classification hyperplane to make the decision function achieve a maximum GMean measure value on the dataset. The above problem is converted into an unconstrained optimization problem to search the optimal weight vector. Experiments are carried out on both Cloud datasets and Knowledge Discovery and Data Mining datasets to evaluate ImSVM. Highly imbalanced training sample sets are constructed. The experimental results show that ImSVM outperforms over-sampling techniques and several existing imbalanced SVM-based techniques.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.12 no.2
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• pp.81-95
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• 2008

In this paper, the negative Polya-Eggenberger distribution has been introduced by compounding negative binomial distribution with beta distribution of I-kind which generates a number of univariate contagious or compound (or mixture of) distributions as its particular cases. The distribution is unimode, over dispersed and all of its positive and negative integer moments exist. The difference equation of the proposed model shows that it is a member of the Ord's family of distribution. Some of its interesting properties have been explored besides different methods of estimation been discussed. Finally, the parameters of the proposed model have been estimated by using a computer programme in R-software. Application of the proposed model to some data, available in the literature, has been given and its goodness of fit demonstrated.

• Bulletin of the Korean Mathematical Society
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• v.45 no.2
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• pp.277-283
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• 2008

The paper deals with the values at the negative integers of a certain Dirichlet series related to the Riemann zeta function and with the expression of these values in terms of Bernoulli numbers.

• School Mathematics
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• v.4 no.2
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• pp.205-222
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• 2002

In school mathematics, the negative numbers have been instructed using the intuitive models such as the number line model, the counting model, and inductive-extrapolation on the additionand multiplication and using inverse operation on the subtraction and division. Theseinstructions on the negative numbers did not present their formal nature and caused the difficulty for students to understand their operations because of the incomplete function of the intuitive models. In this study, we tried to improve such problems of the instructions of the negative numbers on the basis of the didactical phenomenological analysis. First of all, we analysed the nature of the negative numbers and the cognitive obstructions through the examination about the historic process of them. Second, we examined hew the nature of the negative numbers were analysed and described in mathematics. Third, we explored the improving directions for them on the ground of the didactical phenomenological analysis. In school mathematics, the rules of operations using the intuitive models of the negative numbers have been Instructed rather than approaching toward the nature of them. The negative numbers have been developed from the necessity to find the general solution of equations. The study tries to approach the operations instructions of the negative numbers formative]y to overcome the problems of those that are using the intuitive models and to reflect the formative Furthermore of the negative numbers. Furthermore, we examine the way of the instruction of the negative numbers in real context so that the algebraic feature and the real context should be Interactive.