• Journal of KIISE:Computer Systems and Theory
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• v.33 no.9
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• pp.634-641
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• 2006

Flash memory has many advantages like non-volatility and fast I/O speed, but it has also disadvantages such as not-in-place-update data and asymmetric read/write/erase speed. For the performance of flash memory storage, it is essential for the buffer replacement algorithms to reduce the number of write operations that also affects the number of erase operations. A new buffer replacement algorithm is proposed in this paper, that delays the writes of not-cold-dirty pages in the buffer cache of flash storage. We show that this algorithm effectively decreases the number of write operations and erase operations without much degradation of hit ratio. As a result overall performance of flash I/O speed is improved.

• Journal of Educational Research in Mathematics
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• v.21 no.3
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• pp.239-259
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• 2011

This study investigated the elementary school students' ability on the algebraic reasoning as generalized arithmetic. It analyzed the written responses from 648 second graders, 688 fourth graders, and 751 sixth graders using tests probing their understanding of the properties of whole number operations. The result of this study showed that many students did not recognize the properties of operations in the problem situations, and had difficulties in applying such properties to solve the problems. Even lower graders were quite successful in using the commutative law both in addition and subtraction. However they had difficulties in using the associative and the distributive law. These difficulties remained even for upper graders. As for the associative and the distributive law, students had more difficulties in solving the problems dealing with specific numbers than those of arbitrary numbers. Given these results, this paper includes issues and implications on how to foster early algebraic reasoning ability in the elementary school.

• The Mathematical Education
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• v.40 no.2
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• pp.195-215
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• 2001

The purpose of this paper is to present a specific set of home teaching methods in hopes to prevent slow learner of the elementary mathematics. This paper deals with the number and operations, one of five topics in the elementary mathematics A survey of two hundred elementary school teachers was made to see the teacher's opinions of the role of home studying and to concretize the contents of the research topics. There were asked which is the most essential contents for the concrete loaming and which is the most difficult monad that might cause slow leaner. And those were found to be; counting, and arithmetic operations(addition and subtraction) of one or two-digit numbers and multiplication and their concepts representations and operations(addition and subtraction) of fractions. The home teaching methods are based on the situated learning about problem solving in real life situations and on the active teaming which induces children's participation in the process of teaching and learning. Those activities in teaching each contents are designed to deal with real objects and situations. Most teaching methods are presented in the order of school curriculum. To teach the concepts of numbers and the place value, useful activities using manipulative materials (Base ten blocks, Unifix, etc.) or real objects are also proposed. Natural number's operations such as addition, subtraction and multiplication are subdivided into small steps depending upon current curriculum, then for understanding of operational meaning and generalization, games and activities related to the calculation of changes are suggested. For fractions, this paper suggest 10 learning steps, say equivalent partition, fractional pattern, fractional size, relationship between the mixed fractions and the improper fraction, identifying fractions on the number line, 1 as a unit, discrete view point of fractions, comparison of fractional sizes, addition and subtraction, quantitative concepts. This research basically centers on the informal activities of kids under the real-life situation because such experiences are believed to be useful to prevent slow learner. All activities and learnings in this paper assume children's active participation and we believe that such active and informal learning would be more effective for learning transfer and generalization.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.5
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• pp.17-23
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• 2004

In this paper, we proposed a mixed algerian to improve decimal division speed. In the binary number system, nonrestoring algorithm has a smaller number of operation than restoring algorithm. In decimal number system however, the number of operations differs with respect to quotient values. Since one digit ranges 0 to 9 in decimal, the proposed mixed algerian employs both nonrestoring and restoring algorithm considering current partial remainder values. The proposed algorithm chooses either restoring or nonrestoring algerian based on the remainder values. The proposed algorithm improves computation speed substantially over a single algorithm decreasing the number of operations.

• Korean Journal of Adult Nursing
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• v.14 no.3
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• pp.428-437
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• 2002

Purpose: The purpose of this study is to examine the changes of surgical patients' body temperature in applying warming to patients. The study of an effective nursing intervention, which aims to prevent hypothermia during surgical operations, use of anesthesia, and to remove dermal discomforts. The nonequivalent control group pre-test/post-test design was used for this quasi-experimental study. Method: The study subjects were adult patients who would take a surgical operation under general anesthesia in C Hospital; the surgical operations done were, total abdominal hysterectomy or Myomectomy; 20 patients were included in experimental group I, 20 patients were included in experimental group II, and 20 patients were in the comparative group. The total number of study subjects was 60. The data was collected from September the 1st, 2001 to October the 20th, 2001. The data was analyzed by SPSS program, F-test and Repeated measures of ANOVA. Multi-comparison method of DUNCAN was used for the sections that show the significant differences at the level of p<.05, which was a posterior examination. Result: 1) "The body temperatures of the three groups of patients will be respectively different at the end of the operations; experimental group I to which warming was applied before the operations, experimental group II to which warming was applied during the operations, and the comparative group with no warming being given," showed (F=12.609, p=.000). 2) "Degrees of shivering symptoms for the three groups will be respectively different at the end of the operations; experimental group I which applied warming before operations, experimental group II which applied warming during operations and the comparative group with no warming." Showed assumed (F=6.626, p=.000). Conclusion: Summing up the above study, the warming assumed during operations was a more effective nursing intervention for preventing patients' hypothermia than the warming assumed before operations.

• Journal of Elementary Mathematics Education in Korea
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• v.19 no.4
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• pp.563-588
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• 2015

In elementary school, didactical transposition is inevitable due to several reasons. In mathematics, addition and multiplication are taught as binary operations, subtraction and division are taught as unary operations. But in elementary school, we try to teach all the four operations as binary operations by didactical transposition. In 'Mastering' the concepts of the four operations, the way of concept introduction is dealt importantantly. So it is different from understanding the four operations. In this study, we analyzed the four operations of natural numbers and fractions from two perspectives: concept understanding (how to introduce concepts and how to choose an operation) and connection between the operations. As a result, following implications were obtained. In division of fractions, students attempted a connection with multiplication of fractions right away without choosing an operation, based on the situation. Also, to understand division of fractions itself, integrate division of fractions presented from the second semester of the fifth grade to the first semester of the sixth grade are needed. In addition, this result can be useful in the future textbook development.

• Journal of Elementary Mathematics Education in Korea
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• v.21 no.3
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• pp.531-546
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• 2017

This study explores the basis for determining priority among the four arithmetical operations in order to provide useful pedagogical content knowledge for teaching the order of operations. The study also discusses the perspective for viewing the order of operations. It presents the following five suggestions based on the results of the discussion. First, teachers should be made to realize that the same result can be obtained on calculation even when subtraction and division are performed first in mixed operations of addition and subtraction and mixed operations of multiplication and division. Second, teachers should understand why the rule of calculating sequentially from the left side of an equation has become customary. Third, teachers should be offered an explanation for the driver of the rule setting that multiplication takes precedence over addition in mixed operations of multiplication and addition. Fourth, the significance of the quantity within parenthesis must be emphasized to teachers. Fifth, teachers must gain an in-depth understanding about the order of operations by getting a description of all the customary and conceptual perspectives on the order of operations when describing the same in the teacher's guide.

• Journal of the Korean Society of Systems Engineering
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• v.11 no.1
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• pp.73-79
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• 2015

This paper describes boundary analysis for modeling Aircraft Carrier Sortie Generation System(CVSGS). An aircraft carrier, as a super system, is a warship going into battle by operating a number of aircraft on deck and it should be lay down a definition about aviation operations interacting between aircraft carrier and carrier air wing in small deck area. For this reason this paper models common aviation support system for generating sortie basic unit of carrier aviation operations unlike to general warship and defines boundaries between this system and aircraft carrier and carrier air wing. This paper analysis activities of aircraft carrier and embarked carrier air wing in carrier aviation operations, and analysis and defines boundaries Aircraft Carrier Sortie Generation System(CVSGS) to perform core functions in interacting between aircraft carrier and embarked carrier air wing.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.3
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• pp.139-143
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• 2014

This paper proposes a simplified DC calculation method for simplified depth coding (SDC) mode of 3D High Efficiency Video Coding (3D-HEVC) to reduce the computational complexity. For the computational complexity reduction, the current reference software of 3D-HEVC employs reference samples sub-sampling method. However, accumulation, branch, and division operations are still utilized and these operations increase computational complexity. The proposed method calculates DC value without those operations. The experimental results show that the proposed method achieves 0.1% coding gain for synthesized views in common test condition (CTC) with the significantly reduced number of computing operations.

• Journal of the Korean Operations Research and Management Science Society
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• v.40 no.2
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• pp.63-77
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• 2015

The territorial air that our sovereignty is being applied to is divided into several zones and areas. In order to use and manage them effectively, these zones and areas have laws, regulations and rules. The number of airspaces (MOA : Military Operation Area) and Ranges that are used in the military are limited and many airbases are being used for training. Currently the central department manages some, and the rest are independent airbases. Therefore, efficient allocation is not performed and the result occurs where airspaces and ranges are allocated unnecessarily. This is increasing the workload of staff leading to unnecessary re-work. To slove problem, this study proposed models for allocating airspaces and ranges using goal programming with multi-objective functions of minimizing the deviations of the target values.