• The KSFM Journal of Fluid Machinery
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• v.18 no.3
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• pp.20-25
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• 2015

In this study, there are 6 mixers that are installed in a 600,000 barrel tank. We identified internal flow characteristics of floating roof tank with varying the number of operation from 4 to 6 because mixer is a variable that influence flow characteristics of the tank. And while varying an angle from Right $60^{\circ}$, Right $30^{\circ}$, Left $30^{\circ}$ to Left $60^{\circ}$, we identified internal flow characteristics of the tank. As a result, maximum velocity of flow was 0.02m/s stationarily when we changed the number of operation from 4 to 6. Maximum velocity of flow by change of an angle was from 0.42m/s to 0.47m/s. Therefore, we identified that these factors don't have a great influence on internal flow characteristics of a tank by investigating results with varying the number of operation and an angle.

• East Asian mathematical journal
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• v.33 no.2
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• pp.199-216
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• 2017

A rational number as operator is eventually that it is considered a mapping. Depending on how selecting domain (the target of operation by rational number) and codomain (including the results of operations by rational number), it is possible to see the rational in two aspects. First, rational numbers can be deal with functions if we choose the target of operation by rational number as a number field containing rationals. On the other hand, if we choose the target of operation by rational number as integral domain $\mathbb{Z}$, then rational numbers can be regarded as partial functions on $\mathbb{Z}$. In this paper, we regard the rational numbers with a view of partial functions, we investigate the theoretical background of the relationship between the multiplication of rational numbers and the composition of rational numbers as operators.

• Journal of the Korea Society of Computer and Information
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• v.4 no.2
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• pp.27-38
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• 1999

This paper proposes a high speed digital neuron processor which uses the residue number system, making the high speed operation possible without carry propagation,. Consisting of the MAC(Multiplier and with Accumulator) operation unit, quotient operation unit and sigmoid function operation unit, the neuron processor is designed through 0.8$\mu$m CMOS fabrication. The result shows that the new implemented neuron processor can run at the speed of 19.2 nSec and the size can be reduced to 1/2 compared to the neuron processor implemented by the real number operation unit.

• The Journal of Korean Society for Radiation Therapy
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• v.6 no.1
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• pp.21-30
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• 1994

To analyze the states of operation of radiotherapy facilities in the period from 1979 to 1992 and to get the base for efficient operation and maintenance of the radiotherapy facilities. Data on the records of annual number of patients operated by each facility; span of suspension of operation, the cost and span of repairing, and parts of oui-of-order in the period from 1979 to 1992 were analyzed. We made a comparative analysis of average annual number of patients, annual span of the suspension of operation, annual cost ratio of repair, span of repairing per break down, and total number of broken parts. We could get following annual number of patients(day), span of the suspension of span ($\%$)(day). annual cost ratio fo repair($\%$), span of repairing per break down(Min-Max, day), and number of broken parts from this analysis. 1. Cobalt unit (Picker C-9) : 10,389(43), 0.4(0.83) 0.07, 1hr-2, 3 2. Linac(Clinac 6/100) : 11,492(50), 4.0(9.57), 0.98, 1hr-30, 12 3. Linac(Clinac 18) : 9.115(44), 12.7(30.5), 3.54, 1hr-108. 41 4. Simulator(Picker Ther-X) : 2,017(9), 0.51(1.3), 0.24, 1hr-2, 7 5. RTP(Capentec Cap-plan) : 528(2), 0.4(0.93), - hrs, - The conclusion obtained from statistical analysis above are as follows. 1. The rate of operation of Cobalt unit($99.6\%$) was higher that of Linear Accelerators ($87.3\%$). The rates operation of Simulator and RTP computer were very close to that of Cobalt unit. 2. In order to raise up the working ratio of accelerator. it is desirable that we keep our engineer to learn a sufficient technical skill and the equipment agent to stock sufficient spare parts. 3. In order to maintain Linear Accelerator efficiently, it is desirable to have annually $2.3\%$ of the purchase price of equiment for repairing.

• The Korean Journal of Emergency Medical Services
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• v.8 no.1
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• pp.199-210
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• 2004

Since the 119 fire department was legally permitted to serve in Emergency Medical Service(EMS)Operation of emergency patients in 1983, 119 EMS operation in general has made a big progress in serving the needs for emergency patients. Currently EMS operation is carried out by 119 EMS unit, private ambulance Co.,etc. But due to the public recognition and volunteers, 119 EMS operation carries the major share of the service. This observation is not surprising in that such a trends occured in Japan 20 years ago. This paper compared the 119 EMS operation conducted by the fire department in Korea with that of Japan in order to draw some inferences from the comparison. The results of the study compared to Japan were as follows: 1. Japan was higher 1.5 times in the number of EMS units per population(100,000), 1.1 times in the number of patient transports per unit. 2. Japan was higher 4.54 times in the number of the 119 EMS personnel per population(100,000), 30.6 times in that per square killometers, 30.6 times per 119 EMS unit, in per ambulance 2.48times. 3. Japan was higher 1.83 times in the number of ambulance per population(100,000), 1.26 times in that per square killo meters. 4. Japan was higher 1.7 times in the number of transport patients per population (100,000), but Korea was higher 2.68 times in the transport patients per EMS personal. 5. Compared to Japan, there was no emergency care related to ALS, for example, such as administering dugs orally and intravenously, interpreting elctrocardiograms, performing endotracheal tube or LMA insertion, using monitors and other complex equipments in Korea.

• The Mathematical Education
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• v.59 no.2
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• pp.167-183
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• 2020

This study is an analysis study on the number and operation area of middle school mathematics curriculum. This study is a literature analysis study that analyzes the historical transition process of number and operation area, and suggests the restructuring direction of mathematics learning contents for numbers and operation areas based on the results. In order to achieve this research purpose, the contents of the number and operation areas suggested from the 1st middle school mathematics curriculum to the 2015 revised middle school mathematics curriculum were considered. In addition, in this study, analysis of the mathematical learning contents of number and operation area was conducted. The details of the study are as follows. First, it was decided as a tertiary mathematics curriculum as a criterion for analysis. Second, a basic analysis framework was developed by subdividing the content of mathematics learning into content elements and terminology elements. Third, on the basis of the developed analysis framework, mathematics learning contents that are the core issues of number and operation area were extracted. Fourth, the extracted mathematics learning contents were compared with foreign curriculum. Finally, based on the analysis results, the direction of restructuring for the number and operation area of middle school was suggested. The results of this study are expected to be the basis for the development of a new curriculum.

• Proceedings of the KIEE Conference
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• 1993.07a
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• pp.489-491
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• 1993

Many optimization problem or multiple attribute, multiple alternative decision making problem may have fuzzy evaluation factors. In this case, fuzzy number operation technique is needed to evaluate and compare object functions which become fuzzy sets. Generally, fuzzy number operations can be defined by extension principle of fuzzy set theory, but it is tedious to do fuzzy number operations by using extension principle when the membership functions are defined by complex functions. Many fast methods which approximate the membership functions such as triangle, trapezoidal, or L-R type functions are proposed. In this paper, a fast fuzzy number operation method is proposed which do not simplify the membership functions of fuzzy numbers.

• The Mathematical Education
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• v.40 no.2
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• pp.335-343
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• 2001

Algebra is important part of mathematics education. Recent days, many mathematics educators emphasize on real world situation. Form real situation, pupils make sense of concepts, and mathematize it by reflective thinking. After that they formalize the concepts in abstract. For example, operation in numbers develops these course. Operation in natural number is an arithmetic, but operation on real number is algebra. Transition from arithmetic to algebra has the cutting point in representing the concepts to mathematics sign system. In this note, we see the cognitive tendency of 10th grade about operation of real number, their cutting point of transition from arithmetic to algebra, and show some methods of helping pupils.

• Journal of the Korea Safety Management & Science
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• v.12 no.4
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• pp.117-125
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• 2010

Today, many companies have introduced an ERP system - an enterprise resources planning - in order to improve corporate credibility through transparent management and for quick responses to market situations through quick decision making. After the construction of an ERP system, many companies are having difficulty in calculating the appropriate number of personnel required for running the system because of a lack of standard for doing so, as well as a lack of pertinent procedures. As a result, the companies are having to resort to a trial-and-error approach. Therefore this paper studied a model for calculating the appropriate number of personnel required for efficiently running an ERP system after its construction, as well as for constantly meeting its performance targets. The developed model was applied empirically to calculate an appropriate number of personnel required, and an organization was set up according to this. Therefore, the purpose of this study was to present an optimized model for calculating the number of personnel required for operating an ERP system, that which addresses problems of existing models, in order to help companies organize the operation personnel and its size, as well as to provide more objectivity to the calculated number of personnel required and to improve credibility.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.145-150
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• 2003

The national subway went under construction in 1971, and after three years of endeavor, Seoul subway line number one opened for traffic in 1974. Line number two went under construction in 1978 and it opened for traffic in 1984. With the use of safety operation for more than 20 years, the life cycle nearly came to an end. Therefore the improvements for the safety operation are unavoidable. The total system should not be affected when the new and conventional systems are overlapped, the system operation is in the initial stage, and it confronts the situation of abnormal operation. However, there is a total lack of experience in construction and improvement for the trains that are in the use of large transport and density headway. In this paper, we propose an improvement method of the subway signalling system using ATO (Automatic Train Operation control scheme) to which the latest Digital ATC is applied, and examine the first application model of ATO system.