• Journal of Korean Elementary Science Education
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• v.28 no.3
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• pp.263-276
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• 2009

The purpose of this study was to analyze the elementary students' selection of representable value and confident method that appear in measuring activities by using a microgenetic method. The participants were seven elementary students in the fourth grade. They performed the same measuring activities six times for the study period. Data were collected by interview and observation with their activity recording papers and video tape transcription. Their activities were recorded and documented for the analysis. Results were as follows. First, in the time measuring activity, elementary students developed desirably as their measuring experience increased, for example they selected a representable value in use of a repeated measurement and used a various method in the domain of a time measurement and they showed an increase of a quantitative observation in the volume domain except in the length domain. Second, in a confident method of a representable value, though they must rely upon a repeated measurement, they only measure repeatedly in the time domain. Also in the time domain, it doesn't get accomplished a exact confidence of a representable value at a shortage of skill about a measurement. Accordingly this study will be implications for teachers to teach a handling abilities of measuring instruments to elementary students and to be promote understanding a nature of measurement.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.39 no.1
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• pp.29-36
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• 2015

Exact comparisons of the thermal conductivities of the base fluid and a nanofluid are very important in the early stages of nanofluid development. A simple procedure of measuring the thermal conductivity of the two fluids by the transient hot wire method and numerically dividing these values is used for this purpose. However, because the experiments are not performed simultaneously and the physical properties of the measurement system are sometimes not properly known, large errors are incurred during the evaluation process. This article proposes a new apparatus for thermal conductivity comparison where the working principle is mainly based on relative measurement rather than absolute measurement. The measuring circuit and data processing steps are explained in detail; a validation test was performed using the well-known glycerine and engine oil.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.1
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• pp.53-58
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• 2011

Ultra-precision miniaturized machine tools essential for manufacturing accurate machine components in micro/meso-scale have been developed. To realize high accuracy using mMTs, geometric errors, which are considered as the main sources of inaccuracy should be identified and compensated. The conventional systems for measuring geometric errors, such as a laser interferometer, can measure only one geometric error in a single setup and they involve complicated measurement procedures. A measurement system using PSDs is a promising alternative but the measurable range of such systems is limited to the active range of the PSDs. The proposed measurement system using PSDs can overcome the limit of small measurable range. Further, the mounting errors that could occur during set-up process can be avoided. In this paper, an algorithm corresponding to the system was analyzed and experiments were carried out.

• Journal of Science Education
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• v.41 no.3
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• pp.480-498
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• 2017

This study analyzed the errors of 6th graders of elementary school in problem solving process of the measurement domain. By analyzing the errors that students make in solving difficult problems, this study tried to draw implications for teaching and learning that can help students reach their achievement standards. First, though the students were given enough time to deal with problems, the fact that about 30~60% of students, based upon the problems given, can't solve them show that they are struggling with a part of measurement domain. Second, it was confirmed that students' understanding of the unit of measurement, such as relationship between units, was low. Third, the students have a low understanding in terms of the fact that once the base is set in a triangle then the height can be set accordingly and from which multiple expressions, in obtaining the area of the triangle, can be driven.

• Applied Microscopy
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• v.31 no.4
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• pp.315-323
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• 2001

In situ TEM heating experiments utilizing kaolinite powder samples result in the following facts. (1) The water recirculation system adopted in the Gatan's heating holder is required to prevent specimen drift above $500^{\circ}C$. (2) Since the degree of phase changes depends on the thickness of powders below $600^{\circ}C$, examinations of both thin and thick specimens are required. (3) Sample preparation using Mo-grids is required for TEM heating experiments above $900^{\circ}C$. At these temperature ranges the effect of heating rate and holding time on the phase transition process increases drastically, so that a programmed temperature control is required. (4) TEM heating experiments of the embedded powders by epoxy for the cross-sectional view was limited due to the severe epoxy movement during heating above $300^{\circ}C$. Better methods of sample preparation are required to overcome this problem.

• Journal of Sensor Science and Technology
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• v.10 no.3
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• pp.187-195
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• 2001

A wireless telemetry measurement system, using ISFETs, was developed for environmental monitoring applications, industrial processes, medical treatments and so on. This system is composed of the measurement part located at remote site and a personal computer(PC) which control whole instrument process. The measurement part transmits measured data to the PC by RF transceiver, and transmitted data are analyzed and handled in the PC. Proposed system utilizing time division multiplexing for the transmission of 3channel ISFET signal. The measurement part has an identification number(ID) so that the PC controls many measurement parts separately. Experiments were performed using pH-ISFETs, and the implemented system operates well within designed specification and accuracy of 0.1 pH.

• The Journal of Industrial Distribution & Business
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• v.11 no.7
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• pp.51-60
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• 2020

Purpose: Recently, Korean cosmetics distribution market has been reorganized with the H&B store. In the domestic cosmetics distribution market, existing brand road shops are decreasing, and multi-shops are leading the H & B stores, which have greatly improved their experience and content. In these environmental changes, the offline distribution channels are turning into the multi-editing shops that have introduced products of various brands and greatly enhanced experiences and contents. Nevertheless, most studies of factors and measurement items for measuring customer experience in the H&B store use Schmitt (1999)'s Strategic Experience Modules (SEMs). Therefore, the purpose of this study is to propose a measure that is practicable through consideration of the in-store customer experience components of the H&B store. Research design, data and methodology: Based on Schmitt's Strategic Experience Modules (SEMs), which are widely used in customer experience marketing, the metric pool was constructed through customer and literature research on H & B store managers. Since then, 101 preliminary surveys and 211 main surveys have been conducted in order to propose a dimension of customer experience and refine the metrics. Results: As a result of the research, H&B store's customer experience was derived from a measurement model consisting of 19 measurement items in total of five dimensions: environmental experience, intellectual experience, behavioral experience, tech experience, and relationship experience. This study analyzed that compared to the existing Schmitt's Strategic Experience Modules (SEMs), (1) emotional experience expanded to environmental experience, (2) Cognitive and relationship experiences are maintained (3) behavioral experience was subdivided into physical and technical experiences. In particular, the environmental experience has been proposed as a major component is an important point because the H&B store recently opened a large flagship store and is competitive in constructing a differentiated space. Conclusions: Related experience was seen as an important component of customer experience in the offline store, but in the process of refining the scale, interaction items with employees of the H&B store were removed, and rather, participation in the APP or SNS channel of the company, event Participation, interaction with other customers, etc. appear to be important, while suggesting the practical implications.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.10
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• pp.635-640
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• 2016

This paper dealt with the deterioration characteristics and an on-line diagnosis equipment for SPDs (surge protective devices). An accelerated aging test was carried out using a $8/20{\mu}s$ standard lightning impulse current to analyze the changes of electrical characteristics and to propose the diagnostic parameters and the criterion for deterioration of ZnO varistor which is the core component of SPDs. Based on the experimental results, an on-line diagnosis equipment for SPD was fabricated, which can measure the total leakage current, reference and clamping voltage. The leakage current measurement circuit was designed using a low-noise amplifier and a clamp type ZCT. A linear controller, the leakage current measurement part and a HVDC were used in the measurement of reference voltage. The measurement circuit of clamping voltage consisted of a surge generator and a coupling circuit. In a calibration process, measurement error of the prototype equipment was less than 3%.

• Korean Journal of Materials Research
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• v.23 no.5
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• pp.293-298
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• 2013

In this study, an HP-mod. type(KHR-45A), which is used as a heater tube material in the pyrolysis process, was evaluated for its carburizing properties. It was confirmed from the microstructural observation of the tubes that the volume fraction of carbide increased and that the coarsening of Cr-carbide generated as a degree of carburization increased. The depth of the hardened layer, which is similar to the thickness of the carburized region of each specimen, due to carburization is confirmed by measurement of the micro-Vickers hardness of the cross section tube, which thickness is similar to that of the carburized region of each specimen. Two types of chromium carbides were identified from the EBSD (electron back-scattered diffraction) image and the EDS (energy-dispersive spectroscopy) analysis: Cr-rich $M_{23}C_6$ in the outer region and Cr-rich $M_7C_3$ in the inner region of tubes. The EDS analysis revealed a correlation between the ferromagnetic behavior of the tubes and the chromium depletion in the matrix. The chromium depletion in the austenite matrix is the main cause of the magnetization of the carburized tube. The method used currently for the measurement of the carburization of the tubes is confirmed; carburizing evaluation is useful for magnetic flux density measurement. The volume fraction of the carbide increased as the measuring point moved into the carburized side; this was determined from the calculation of the volume fraction in the cross-section image of the tubes. These results are similar to the trends of carburization measurement when those trends were evaluated by measurement of the magnetic flux density.

• Journal of Elementary Mathematics Education in Korea
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• v.18 no.1
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• pp.37-62
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• 2014

In this thesis, we inquire into teaching method of decimal fraction concept in elementary mathematics education based on measurement activity. For this purpose, our research tasks are as follows: First, we design a experimental learning-teaching plan of 'decimal fraction' unit in 4th grade textbook and verify its effect. Second, after teaching experiment using experimental learning-teaching plan, we analyze the student's status of understanding about decimal fraction concept. As stated above, we have performed teaching experiment which is ruled by new lesson design and analysed the effects of teaching experiment. Through this study, we obtained the following results. First, introduction of decimal fraction based on measurement activity promotes student's understanding of measuring number and decimal notation. Second, operator concept of decimal fraction is widely used in daily life. Its usage is suitable for elementary mathematics education within the decimal notation system. Third, a teaching method of times concepts using place value expansion of decimal fraction is more meaningful and has less possibility of misunderstanding than mechanical shift of decimal point. Fourth, teaching decimal fraction through the decimal expansion helps students with understanding of digit 0 contained in decimal fraction, comparing of size and place value. Fifth, students have difficulties in understanding conversion process of decimal fraction into decimal notation system using measurement activity. It can be done easily when fraction is used. However, that is breach to curriculum. It is necessary to succeed research for this.