• Korean Journal of Child Studies
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• v.11 no.2
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• pp.5-23
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• 1990

The purpose of this study was to investigate the acquisition of number-word systems of young children. Specifically, the acquisition of Korean Number-Words(KNW) was compared with the acquisition of Chinese-derived Number-Words(CNW). The subjects included 120 children aged 2:5 to 5:11. The subjects oral counting using the two number word systems were audiotaped. Two coders transcribed the tapes. The data were analyzed by content analysis with descriptive statistics. The findings of this study showed that the acquisition of KNW began from around age two and the acquisition of CNW from around age three. From then, the acquisition of the two number-word systems was parallel. The acquisition of number-words began from the age of 2 years, increased slowly to the age of 4. and then increased rapidly after the age of 5. Although KNW were acquired earlier than CNW, at around the age of 5 years the acquisition of CNW surpassed the acquisition of KNW. The acquisition of number words consists of four developmental levels: Level I: beginning of acquisition of traditional KNW only Level II: beginning of acquisition of CNW with extension of KNW Level III: parallel extension of the two number-word systems Level IV: superior acquisition of CNW. The major error through all stages in the sequence of number words was the omission of one number-word. Younger children produced errors of omission of one, two or three number-words, whereas older children produced errors of nonstandard number-words and repetition.

• The Mathematical Education
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• v.45 no.1 s.112
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• pp.61-74
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• 2006

The ability of understanding the number and number systems, grasping the properties of number systems, and manipulating number systems is the foundation to understand algebra. It is useful to deepen students' mathematical understanding of number systems and operations. The authentic understanding of numbers and operations can make it possible for the students to manipulate algebraic symbols, to represent relationship among sets of numbers, and to use variables to investigate the properties of sets of numbers. The high school students need to understand the number systems from more abstract perspective. The purpose of this study is to study on understanding and application ability of eleventh graders of basic properties of operations with real numbers.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.299-299
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• 2000

In this paper, a determination method of number of AGVs fer introducing to the multi-path material handling systems is presented by using genetic algorithm. For serving the raw material to each work stations automatically, there needs to introduce a AGVs for transfer the raw martial. To reduce the overall production cost in the material handling systems, however, a trade off exists between the amount of inventory hold on the shop floor and the number of AGVs needed to provide adequate service. In this paper, firstly a objective function which included the net present fixed costs of each stations and each purchased AGVs, delivering cost. stock inventory cost, and safety stock inventory cost is presented. Secondly by using genetic algorithm, the optimal reorder quantity at each stations is decided, where the number of AGVs is increased step by step. From a simulation with different GA parameters, we can determine a optimal number of AGVs to reduce the overall production cost. Thus, the effectiveness of GA for determining the number of AGVs is verified in automated material handling systems.

• East Asian mathematical journal
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• v.31 no.5
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• pp.677-684
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• 2015

In [7], it was shown that Euclidean rings R of imaginary quadratic integers admit unitary number systems. In this paper, as an application of the result, we obtain all self similar tiles arising from the unitary number systems of R.

• East Asian mathematical journal
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• v.31 no.3
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• pp.357-362
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• 2015

For a ring R of imaginary quadratic integers, using a concept of a unitary number system in place of the Motzkin's universal side divisor, we show that the following statements are equivalent: (1) R is Euclidean. (2) R has a unitary number system. (3) R is norm-Euclidean. Through an application of the above theorem we see that R admits binary or ternary number systems if and only if R is Euclidean.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2002.12a
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• pp.46-49
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• 2002

We propose some properties of hybrid number the addition of fuzzy number and random variable and test the fuzzy hypotheses by agreement index for the hybrid number.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.3
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• pp.61-69
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• 2019

The concept of carsharing involves sharing a small number of reserved cars to be used individually by a larger number of people as required. This study examines the operating parameters of one-way carsharing systems in order to determine the appropriate operating conditions that minimizes the lost sales rate. Five operating parameters are tested in this study: the number of stations, the average number of vehicles per station, the rate of one-way trip, the average number of staffs per station, and the relocation policy. The performance of round-trip carsharing systems is also compared to that of one-way carsharing systems. A simulation model is developed and simulations are performed to determine the appropriate combination of operating parameter and levels. The simulation results show that the average number of vehicles per station is the most critical parameter. Other key findings obtained from this research are as follows. First, applying the appropriate relocation policy to one-way carsharing systems can allow more customers to rent vehicles than the traditional round-trip carsharing systems. Second, the appropriate relocation policy should be selected based on the average number of vehicles per station in order to minimize the lost sales rate. Third, the number of stations does not affect the lost sales rate. This study findings will provide tools to understand impact of the carsharing system parameters on the efficiency of the carsharing operations.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2003.05a
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• pp.18-21
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• 2003

We propose some properties of fuzzy conditional expectation of hybrid number the addition of fuzzy number and random variable using Cartesian product distance for ${\alpha}$-level sets.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.4
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• pp.57-66
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• 2004

This paper proposes the design of a 2,048-bit RSA based on RNS(residue number systems) Montgomery modular multiplier As the systems that RNS processes a fast parallel modular multiplication for a large word partitioned into small words, we introduce Montgomery reduction method(MRM)［1］based on Wallace tree modular multiplier and 33 RNS bases with 64-bit size for RNS Montgomery modular multiplication in this paper. Also, for fast RNS modular multiplication, a modified method based on Chinese remainder theorem(CRT)［2］ is presented. We have verified 2,048-bit RSA based on RNS using Samsung 0.35${\mu}{\textrm}{m}$ technology and the 2,048-bit RSA is performed in 2.54㎳ at 100MHz.

• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.134-137
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• 1999

The MC-CDMA(Multi-Code CDMA) systems for handling various data transmission rate which is demanded in the IMT-2000 systems are effective transmission technology, which can provide the higher data service than the conventional IS-95 CDMA systems because a user takes advantage of a number of channels. The receiver of MC-CDMA systems to be provided these data service have to be structured of demodulating simultaneously a number of traffic channels. This paper is designed the merged rake receiver demodulating simultaneously a number of traffic channels in the MC-CDMA systems. The merged rake receiver is to reduce the complexity of receiver resulting a number of channels.