• Journal of Educational Research in Mathematics
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• v.13 no.1
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• pp.57-75
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• 2003

The goal of this paper is to offer material which make mathematising Fruedenthal(1991) proposed be experienced through the process of teaching and learning mathematics. In this paper, the number of unit squares a diagonal passes through for an m$\times$n lattice rectangle is studied and its generalization is discussed. Through this discussion, the adaptability of this material Is analysed. Especially, beyond inductional conjecture, the number of unit squares is studied by more complete way, and generalization in 3-dimension and 4-dimension are tried. In school mathematics, it is enough to generalize in 3-dimension. This material is basically appropriate for teaching and learning mathematising in math classroom. In studying the number of unit squares and unit cubes, some kinds of mathematising are accompanied. Enough time are allowed for students to study unit squares and unit cubes to make them experience mathematising really. To do so, it is desirable to give students that problem as a task, and make them challenge that problem for enough long time by their own ways. This material can be connected to advanced mathematics naturally in that it is possible to generalize this problem in n-dimension. So, it is appropriate for making in-service mathematics teachers realize them as a real material connecting school mathematics and advanced mathematics.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.35 no.4
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• pp.53-60
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• 2019

This study intends to examine the changes found in the unit floor plans of the apartments built in Beijing from 1979 to 2018. For the 3 - bedroom type apartments, 40 unit floor plans were collected, and the changes of integration values of each space were analyzed periodically in four phases. The unit floor plans are analyzed in the context of the Space Syntax Model and compared to the lifestyle and societal changes in China. The results of the study indicate the followings: As time went by, the living room and the dining room were separated from each other with the increasing area of the apartment unit floor plans. The function of the integrated living room was dispersed, and the integration of the living room and the dining room decreased with the change of time. In the third phase, the dining room occupied the center of the unit floor plans with the highest integration value; Chinese people prefer to place the kitchen in the relatively deep place in order to prevent oil and smoke caused by their cooking habits like stir-fry; The privacy of the master bedroom has been strengthened.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.7
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• pp.289-302
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• 2019

Structural change of time series means that the distribution of observations is relatively stable in the period of constituting the entire time series data, but shows a sudden change of the distribution characteristic at a specific time point. Within a non-stationary long-term time series, it is important to determine in a timely manner whether the change in short-term trends is transient or structurally changed. This is because it is necessary to always detect the change of the time series trend and to take appropriate measures to cope with the change. In this paper, we propose a method for decision makers to easily grasp the structural changes of time series by visualizing the test results based on the unit root test. Particularly, it is possible to grasp the short-term structural changes even in the long-term time series through the method of dividing the time series and testing it.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.12 no.3
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• pp.52-57
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• 2003

In this paper, stability of ultra precision cutting unit is analyzed and this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for unit control.

• Quality Improvement in Health Care
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• v.8 no.1
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• pp.22-42
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• 2001

Background : A study comparing unit dose drug distribution system(UDS) versus traditional drug distribution system(TDS) was conducted in Seoul National University Hospital. The objectives of this study were to identify safer drug distribution system and to measure the efficiency of both systems in utilizing nursing and pharmacist's time. Methods : The study was designed to compare the data on medication errors, nursing time and pharmacists' time before and after implementation of the UDS in the internal medicine and otorhinolaryngology care units. The data on actual medications administered to patients were obtained by a disguised observer during the study period. The data collected were then compared with the physicians' orders to determine the rate of medication errors. In addition, using ten-minute interval work-sampling method nursing and pharmacists' time were measured. Results : About 6% of medications were administered incorrectly in the TDS, in comparison to 1.6% in the UDS. The rate of medication error decreased significantly in the UDS compared with the TDS. Mean times spent on medication-related activities by nurses were 34.1% in the TDS and 28.5% in the UDS. In the internal medicine care unit, nursing time associated with medications decreased significantly after the implementation of the UDS, but the reduction in medication-related nursing time in the otorhinolaryngology care unit was not significant. Pharmacist's medication-related work activities, increased from 2% in the TDS to 20% in the UDS. Pharmacist's time spent on therapy-related activities increased significantly. Conclusion : The rate of medication errors in the UDS decreased significantly compared with the TDS. Time spent on medication-related activities decreased for nurses while it increased for pharmacists. In summary, the UDS was estimated to be safer and to utilize of pharmacists' and nursing time more efficiently than the TDS.

• Journal of Ocean Engineering and Technology
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• v.13 no.4 s.35
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• pp.63-74
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• 1999

This study has been investigated about the influence of moisture environment on the mechanical properties in the carbon fiber cross laminates. And it has been also investigated the effect of unit ply thickness of the carbon fiber cross laminates on the mechanical properties in distilled water of $80^{\circ}C$ for a certain period of time. As a results, it was found that the weight gain of water was increased with the immersion time and the bending strength and fracture toughness were decreased with the weight gain of water. And it was also shown that the bending strength and fracture toughness were decreased with the increasing of the unit ply thickness of carbon fiber cross laminates through the immersion time.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.21 no.48
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• pp.201-211
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• 1998

The fundamental object of work measurement is to precisely establish the time standards, which are the indices of labor productivity. This study discussed the development of robot work measurement method that could establish the time standard effectively. In manufacturing industries the various robot tasks are generally classified and standardized by the unit motions. The Robot Modularization of the Unit Motion (ROMUM) was realized by the module of two steps GET and PUT unit motions. This method reduced time and effort of analysis, and could be done with ease. Therefore, ROMUM will increase the convenience of use for the unskilled worker and decrease the time required, cost and errors. And, it will contribute to reduce the unnecessary motion by robot motion analysis.

• Journal of Korean Society for Quality Management
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• v.20 no.2
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• pp.137-142
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• 1992

MODAPTS has been widely used for establishing the standard time of manual works because of easy application of the system. However this system was developed based on MTM, winch was one of the low task standard. Also in this system, it usually becomes a cause of error in accuracy that all the simultaneous motions(SIMO) should be analyzed in the sequent motions of two hands. In order to improve the weak points of MODAPTS, the structure of time unit and SIMO of MODAPTS was researched, and HITMAP was developed on the basis of Work Factor System which was one of the high task standard. HITMAP is composed of 26 standard elements and it's time unit is MD(1MD=0.1 second) and MGSRMPS is the motion pattern of HITMAP. In this study HITMAP shows more than 95% of accuracy to WF. Therefor, it is expected that HITMAP can be used for the improvement of productivity and incentive systems.

• Current Optics and Photonics
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• v.4 no.3
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• pp.186-192
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• 2020

This paper describes a real-time monitoring system in Ethernet passive optical networks (EPON) that uses burst-mode fiber Bragg grating (FBG) optical sensors. The FBG interrogation unit in the optical line terminal (OLT) transmits the monitoring wavelength to optical network units (ONUs). The FBG sensor unit in each ONU returns a burst-mode monitoring signal to the OLT. As the system applies time division multiple access (TDMA), a uniform Bragg wavelength can be used to monitor the EPON system. The FBG interrogation unit analyzes the received burst-mode monitoring signals and outputs fault information on the ONU branches in EPON. The simulation results show the effectiveness of the proposed monitoring system based on TDMA. In addition, we compared the proposed TDMA-based monitoring system with a WDMA-based monitoring system.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.116-117
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• 2013

The real time simulator for testing the high power inverter unit of a PM synchronous motor is proposed. The power converter of the real time simulator can replaces the dynamo test equipment that consists of a PMSM(PM synchronous motor) and load unit. It is verified by the simulation that the real time simulator has a similar electrical and mechanical characteristics of the PM synchronous motor.