• Journal of the Korean Society for information Management
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• v.13 no.2
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• pp.97-120
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• 1996

This study reports the results of an exploratory investigation into building number technique applied by a sample of novice students using Electronic Dewey(ED). For control purposes, a second sample used the same classification schedule but in print format. In this experiment, the DDC 20 in print had a higher success rate than ED. While the searches in ED took shorter time than DDC in print, students using DDC 20 in print were able to build more correct numbers than ED. Novice users did not take full advantage of system features of ED. Therefore, it is important to note the overall difficulty with which users could build numbers from the ED after little training. However, it is interesting to note that the students in the CD-ROM group were more interested in building numbers than their colleagues in the Print group. The correlation between the grade of English course and the score in experiment was negative in Print group. And the correlation between GPA and the score in experiment was a little positive. The correlation between the time and the score in experiment was quitenegative.

• International journal of advanced smart convergence
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• v.13 no.2
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• pp.35-43
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• 2024

In this paper, we propose two 127-bit LFSR (Linear Feedback Shift Register)-based OTP (One-Time Password) generators. One is a 9-digit decimal OTP generator with thirty taps, while the other is a 12-digit OTP generator with forty taps. The 9-digit OTP generator includes only the positions of Fibonacci numbers to enhance randomness, whereas the 12-digit OTP generator includes the positions of prime numbers and odd numbers. Both proposed OTP generators are implemented on an Arduino module, and randomness evaluations indicate that the generators perform well across six criteria and are straightforward to implement with Arduino.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.12
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• pp.20-35
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• 2016

In this paper, in order to reduce the delay and area of the partial product accumulation (PPA) of the parallel decimal multiplier, a tree architecture that composed by multi-operand decimal CSAs and improved CLA is proposed. The proposed tree using multi-operand CSAs reduces the partial product quickly. Since the input range of the recoder of CSA is limited, CSA can get the simplest logic. In addition, using the multi-operand decimal CSAs to add decimal numbers that have limited range in specific locations of the specific architecture can reduce the partial products efficiently. Also, final BCD result can be received faster by improving the logic of the decimal CLA. In order to evaluate the performance of the proposed partial product accumulation, synthesis is implemented by using Design Complier with 180 nm COMS technology library. Synthesis results show the delay of the proposed partial product accumulation is reduced by 15.6% and area is reduced by 16.2% comparing with which uses general method. Also, the total delay and area are still reduced despite the delay and area of the CLA are increased.

• Journal of the Korean Society for Library and Information Science
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• v.46 no.3
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• pp.57-78
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• 2012

Of the collection of public libraries in Korea, the literature collection is the largest, and Korean fictions, about 14% of the entire collection constitute the largest single subject. However, in the Korean Decimal Classification(KDC) Korean fiction is represented in one section, that is, 813 which corresponds to the only one of thousand divisions. More specifically, only two sub-sections, 813.6 and 813.7 are supposed to be assigned to the huge collection of modern Korean fiction, and, in reality, only 813.6 is being used in most libraries. Even with the use of book numbers, such disproportionate allocation of classification numbers would definitely lower the discriminative capacity of call numbers given to each item. It would also bring about difficulties in both shelving, on the libraries' side, and finding items from shelf, on the users' side. This study aims to examine the issues related to classifying Korean fictions in public libraries, including the composition of KDC schedules and the actual practice of classification, and then proposes the measures for improving the classification of Korean fictions.

• Journal of Information Processing Systems
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• v.13 no.3
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• pp.573-589
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• 2017

Cloud computing is an attractive solution that can provide low cost storage and powerful processing capabilities for government agencies or enterprises of small and medium size. Yet the confidentiality of information should be considered by any organization migrating to cloud, which makes the research on relational database system based on encryption schemes to preserve the integrity and confidentiality of data in cloud be an interesting subject. So far there have been various solutions for realizing SQL queries on encrypted data in cloud without decryption in advance, where generally homomorphic encryption algorithm is applied to support queries with aggregate functions or numerical computation. But the existing homomorphic encryption algorithms cannot encrypt floating-point numbers. So in this paper, we present a mechanism to enable the trusted party to encrypt the floating-points by homomorphic encryption algorithm and partial trusty server to perform summation on their ciphertexts without revealing the data itself. In the first step, we encode floating-point numbers to hide the decimal points and the positive or negative signs. Then, the codes of floating-point numbers are encrypted by homomorphic encryption algorithm and stored as sequences in cloud. Finally, we use the data structure of DoubleListTree to implement the aggregate function of SUM and later do some extra processes to accomplish the summation.

• Journal of Educational Research in Mathematics
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• v.25 no.3
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• pp.263-279
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• 2015

The introduction of real numbers is one of the most difficult steps in the teaching of school mathematics since the mathematical justification of the extension from rational to real numbers requires the completeness property. The author elucidated what questions about real numbers can be unanswered as the "institutional didactic void" in school mathematics defining real numbers as the union of the rational and irrational numbers. The pre-service teachers' explanations on the extension from rational to real numbers and the raison d'$\hat{e}$tre of arbitrary non-recurring decimals showed the superficial and fragmentary understanding of real numbers. Connecting school mathematics to university mathematics via the didactic void, the author discussed how pre-service teachers could break the illusion of transparency about the real number.

• Communications of Mathematical Education
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• v.36 no.4
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• pp.469-486
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• 2022

Counting occupies a fundamental and important position in mathematical learning due to its relation to number concepts and numeral operations. In particular, counting up to large numbers is an essential learning element in that it is structural counting that includes the understanding of place values as well as the one-to-one correspondence and cardinal principles required by counting when introducing number concepts in the early stages of number learning. This study aims to derive didactical implications by investigating the possibility of and the strategies for counting large numbers that is expected to have no students' experience because it is not composed of current textbook activities. To do this, 89 second-grade elementary school students who learned the three-digit numbers and experienced group-counting and skip-counting as textbook activities were provided with questions asking how many penguins were in a picture where 260 penguins were irregularly arranged and how to count. As a result of analyzing students' responses in terms of the correct answer rate, the strategy used, and their cognitive characteristics, the incorrect answer rate was very high, and the use of decimal principles, group-counting, counting by one, and partial sum strategies were confirmed. Based on these analysis results, several didactical implications were derived, including the need to include counting up to large numbers as textbook activities.

• Journal of Korean Library and Information Science Society
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• v.24
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• pp.449-484
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• 1996

The purpose of this study is to analyze the structural model of classification, to compare enumerative schemes with faceted schemes and finding the facted schems used in the Dewey Decimal Classification. The Structural model of classifications can be divided to enumerrative schemes and facted schemes(analytico-synthetic schemes). Enumerative schemes represent the various kind of subject in different ways and have to not only list all existing combinations of subjects but also any of potential subjects. Faceted schemes is the decomposition of concepts into all possible characteristics which are known as facets. DDC was originally created as enumerative, but over 20 editions has moved increasing towards synthetic features such as the add instructions, and the seven auxiliary tables. Many DDC class numbers found in the Schedules may be subdivied by another number(or part of it) that has been drawn from the Schedules or auxiliary tables. This process of subdividing class numbers is called number building and it can be done only when there are number building instruction in the Schedules or Tables.

• 전기의세계
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• v.28 no.6
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• pp.61-77
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• 1979

This paper is concerned with minimization process of the binary logic function. This paper describes an algorithm called the SIMPLE TABLE METHOD that well suited to minimization a switching function of any number of variables. For the Simple Table construction, a theorem based upon the numerical properties of the logic function is derived from the relationships governing minterms of the given function. Finally the minimal sum of products can be obtained in terms of the Direct Method or the Indirect Method from the table and table characteristics derived from the Simple Table. The properties and table characteristics used in this paper are described. All the minterms of a switching function are manipulated only by decimal numbers, not binary numbers. Some examples are used as a vehicle to guide the readers who are familiar with the Karnaugh map and Quine-McCluskey tabular method to this New method. These examples not only treat how to handle Don't Care miterms but also show the multiple output functions.

• Journal of the Korean Society for Library and Information Science
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• v.44 no.2
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• pp.117-137
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• 2010

The purposes of this study are to review the historical development of food and culture in the KDC (Korean Decimal Classification) and to propose improvements of the KDC to classify materials of food and culture by using the KDC effectively. First of all, changes of classification numbers and headings related to food and culture from the 1st edition to the 5th edition of the KDC were examined. Recent books about food and culture were examined and were classified according to the latest edition of the KDC. Several problems were found including a lack of headings, including notes in food and culture, a lack of headings about Korean foods in particular and reflections about various foods from other countries, a lack of detailed relative headings, and the remaining western oriented headings. Other classification systems about food and culture were analyzed and it was found that there was a need to have new headings for classifying Korean traditional foods and table services, new formats for a relative index, detailed notes, and changes in western oriented headings.