• International Journal of Precision Engineering and Manufacturing
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• v.7 no.1
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• pp.3-8
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• 2006

This paper deals with an automated computer-aided process planning and die design system by which designer can determine operation sequences even if they have a little experience in process planning and die design for axisymmetric products. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM softwares, DEFORM and ANSYS, to form a useful package. The system can provide a flexible process based on either the reduction in the number of forming sequences by combining the possible two processes in sequence, or the reduction of deviation of the distribution on the level of the required forming loads by controlling the forming ratios. Especially in die design module optimal design technique and horizontal split of die insert were investigated for determining appropriate dimensions of components of multi-former die set. Results obtained, using the modules, enable the design and manufacture of a die set for a multi-former to be more efficiently performed.

• Communications of the Korean Mathematical Society
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• v.35 no.4
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• pp.1057-1073
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• 2020

In this paper, we study some of the factorization aspects of rational multicyclic monoids, that is, additive submonoids of the nonnegative rational numbers generated by multiple geometric sequences. In particular, we provide a complete description of the rational multicyclic monoids M that are hereditarily atomic (i.e., every submonoid of M is atomic). Additionally, we show that the sets of lengths of certain rational multicyclic monoids are finite unions of multidimensional arithmetic progressions, while their unions satisfy the Structure Theorem for Unions of Sets of Lengths. Finally, we realize arithmetic progressions as the sets of distances of some additive submonoids of the nonnegative rational numbers.

• Communications of the Korean Mathematical Society
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• v.18 no.3
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• pp.459-468
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• 2003

In this paper, we introduce and study a new class of the generalized set-valued mixed variational inequalities. Using the resolvent operator technique, we construct a new iterative algorithm for solving this class of the generalized set-valued mixed variational inequalities. We prove the existence of solutions for the generalized set-valued mixed variational inequalities and the convergence of the iterative sequences generated by the algorithm.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.7
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• pp.525-530
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• 2004

A classifier was constructed by using a generalized regression neural network (GRU) and random generator (RG), which was applied to classify DNA sequences. Three data sets evaluated are eukaryotic and prokaryotic sequences (Data-I), eukaryotic sequences (Data-II), and prokaryotic sequences (Data-III). For each data set, the classifier performance was examined in terms of the total classification sensitivity (TCS), individual classification sensitivity (ICS), total prediction accuracy (TPA), and individual prediction accuracy (IPA). For a given spread, the RG played a role of generating a number of sets of spreads for gaussian functions in the pattern layer Compared to the GRNN, the RG-GRNN significantly improved the TCS by more than 50%, 60%, and 40% for Data-I, Data-II, and Data-III, respectively. The RG-GRNN also demonstrated improved TPA for all data types. In conclusion, the proposed RG-GRNN can effectively be used to classify a large, multivariable promoter sequences.

• Proceedings of the Korea Contents Association Conference
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• 2007.11a
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• pp.12-16
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• 2007

The function of a protein is closely co-related with its subcellular location(s). Given a protein sequence, therefore, how to determine its subcellular location is a vitally important problem. We have developed a new prediction method for protein subcellular location(s), which is based on n-gram feature extraction and k-nearest neighbor (kNN) classification algorithm. It classifies a protein sequence to one or more subcellular compartments based on the locations of top k sequences which show the highest similarity weights against the input sequence. The similarity weight is a kind of similarity measure which is determined by comparing n-gram features between two sequences. Currently our method extract penta-grams as features of protein sequences, computes scores of the potential localization site(s) using kNN algorithm, and finally presents the locations and their associated scores. We constructed a large-scale data set of protein sequences with known subcellular locations from the SWISS-PROT database. This data set contains 51,885 entries with one or more known subcellular locations. Our method show very high prediction precision of about 93% for this data set, and compared with other method, it also showed comparable prediction improvement for a test collection used in a previous work.

• Communications of Mathematical Education
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• v.28 no.4
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• pp.529-552
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• 2014

Recently, mathematical reasoning has been considered as one of the most important mathematical thinking abilities to be established in school mathematics. This study is to investigate the mathematical problems on the content of 'Set and Statement' and 'Sequences' in high school according to the four types of reasoning, namely Making Conjectures, Investigating Conjectures, Developing Arguments, and Evaluating Arguments. Those types of reasoning were reconstructed based on Johnson's six types of reasoning suggested in 2010. The content is dealt with in 'Mathematics II' textbook developed and published according to the mathematics curriculum revised in 2009. The subject of this study is nine types of textbooks and mathematical problems in the textbook are consisted of as two parts of 'general problem' and 'evaluation problem'. Finally, the results of this study can be summarized as follow: First, it is stated that students be establishing a logical justification activity, the highest reasoning activity through dealing with the 'Developing Arguments' type of problems affluently in both 'Set and Statement' and 'Sequence' chapters of Mathematics II textbook. Second, it is mentioned that students have an chance to investigate conjectures and develop logical arguments in 'Set and Statement' chapter of Mathematics II textbook. In particular, whereas they have an chance to investigate conjectures and also develop arguments in 'Statement', the 'Set' chapter is given only an opportunity of developing arguments. Third, students are offered on an opportunity of reasoning that can make conjectures and develop logical arguments in 'Sequences' chapter of Mathematics II textbook. Fourth, Mathematics II textbook are geared to do activities that could evaluate arguments while dealing with the problems relevant to 'mathematical process' included in 'general problem'.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.4C
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• pp.318-323
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• 2006

In this paper we propose three methods to generate short hopping sequences for the frequency hopping system. First, we explain the one coincidence set of sequences and the polyphase power residue seqences which have been known previously, and we suggest a method by modifying the one coincidence sequence and two methods by using the power residue sequences. We verify that the optimal position deleted-power residue sequences have the best Hamming autocorrelation property and the first position deleted-power residue sequences and the modified one coincidence sequences follows with respect to Hamming autocorrelation. We also explain that these sequences have the good balance property and can be implemented with low complexity.

• Communications of the Korean Mathematical Society
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• v.17 no.2
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• pp.215-220
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• 2002

Since P. Erdos introduced the concept of "subset-sum-distinctness", lots of mathematicians have been interested in a "dense" set having distinct subset sums. In this paper, we establish a couple of theorems on maximal subset-sun-distinct sequence with respect to the set inclusion.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.7A
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• pp.1257-1263
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• 2001

In the paper, the p-ranks and characteristics polynomials of cyclic difference sets are derived by expanding the trace expression of their characteristic sequences. By using this method, it is shown that the 3-ranks and characteristic polynomials of Helleseth-Kumar-Martinsen (HKM) difference set and Lin difference set can be easily obtained.

• Journal of applied mathematics & informatics
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• v.9 no.1
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• pp.239-252
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• 2002

A sort sequence $S_n$ is sequence of all unordered pairs of indices in $I_n$={1,2,…n}. With a sort sequence $S_n$ = ($s_1,S_2,...,S_{\frac{n}{2}}$),one can associate a predictive sorting algorithm A($S_n$). An execution of the a1gorithm performs pairwise comparisons of elements in the input set X in the order defined by the sort sequence $S_n$ except that the comparisons whose outcomes can be inferred from the results of the preceding comparisons are not performed. A sort sequence is said to be extremal if it maximizes a given objective function. First we consider the extremal sort sequences with respect to the objective function $\omega$($S_n$) - the expected number of tractive predictions in $S_n$. We study $\omega$-extremal sort sequences in terms of their prediction vectors. Then we consider the objective function $\Omega$($S_n$) - the minimum number of active predictions in $S_n$ over all input orderings.