• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.62-63
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• 2004

• Proceedings of the Korean Fiber Society Conference
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• 1997.04a
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• pp.127-133
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• 1997

Authors measured the apparent contact angle in a yarn using microscope because it gives a useful information in the evaluation of comfort factors in fabrics. The mechanical stage of microscope was designed and built to facilitate this measurement. Variables examined were the fiber type, the twisting number, and the fluid type. All produced significant effect most of which could be rationalized based on the known concepts. The methodology used and the results obtained are discussed in detail.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.857-862
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• 2003

In this paper, we concern for development of precise measuement system for civil structure by using one chip microprocessor based on communication system. The datalogger is developed by using 80C196KC microprocessor. It has RF communication modul and data acquisition function for several kinds of sensors such as load cell, tilt-meter, strain gauge, tension meter, themocouple and so on. The data is acquisited by datalogger is sent to a main server which is located at central monitoring office. The server has a function suppervising several data points located at civil structures, it analyzes the data and shows the data graphically. The effectiveness of the developed system is proven through experimental results by an application for the bridge of Nakdong river edge in Busan, Korea.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.220-223
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• 1997

Moire topography method is a well-known non-contacting 3-D measuement method. Recently, the automatic 3-D measurement by moire topography has been required since the method was frequently applied to the engineering and medical fields. 3-D measurement using projection moire topography is very attractive because of it's high measuring speed and high sensitivity. In this paper, using two-wavelength method of projection moire topography tested to measuring object with the 2x-ambiguity problem. Experimental results prove that the proposed scheme is capable of finding absolute fringe orders, so that the 2x-ambiguity problem can be effectively overcome so as to treat large step discontinuities in measured objects.

• Korean Journal of Optics and Photonics
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• v.5 no.2
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• pp.198-203
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• 1994

An improved method for the measuement of very long radius of curvature by using a bidirectional shearing interferometer in a noncollimated light beam is given. This method can be used for both lenses and surfaces with positive or negative power. Detailed analyses for optical arrangements and achievable accuracy are presented.sented.

• Journal of Nutrition and Health
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• v.30 no.3
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• pp.277-285
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• 1997

The purpose of this study was to investigate the relationship among nutrient intake, life style, and serum lipids level in 108 healthy middle-aged men in Taegu. A convenient method was to assess nutritional intake. Anthropometric measuement of body weight and hight were measured and average energy expenditure was calculated. The mean body mass index(BMI) was 22.8$\pm$2.4 and it was in the middle of the mean BMI of Korean men. Obesity rate of study subject were 13.2%. Daily energy intake was not sufficient as 88.4% of recommended dietary allowances and the energy percentage of carboydrate, fat protein was 65 : 21 : 14. Mean intake of vitamin A, B1, C and Ca were lower than RDA. There was a highly significant negative correlation between the systolic blood pressure and calcium intake(r=-0.28, p<0.05). Smokers showed significantly higher blood glucose than non-smokers. Skipping meals and uneven diurnal distribution(no breakfast and large evening meals) are associated with high triglyceride level in this population. There was a highly significant correlation between body weight and plasma lipids. Energy expenditure was negatively correlated with plasma triglyceride level. Especially, atherogenic index was significantly lower in job-time physically active worker than that in sedentary worker. Above data provides valuable imformation to the community for program planning as well as to health providers who work individual male adults to meet their nutrition needs and to control blood lipids.

• Journal of the Korean Society of Combustion
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• v.7 no.2
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• pp.7-14
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• 2002

The probability density functions (PDF) of temperature were measured by coherent anti-Stokes Raman Spectroscopy (CARS) in flames of gas turbine combustor sector rig of an aero-engine. The combustor was operated at simulated ground idle conditions with standard kerosene fuel. Temperature PDFs had been measured near fuel nozzle with change of rotation of a swirler and existence of a prefilmer. The characteristic features of temperature PDFs showed the variation of combustion configurations at four experimental conditions. Without a prefilmer, large recirculation of high temperature gas was expected in the co-flow condition and un vaporized fuel fragments were detected in the counter-flow condition. With a prefilmer, the enhanced mixing increased combustion intensity near fuel nozzle in the counter-flow condition and the flame was attached far from the fuel nozzle in the co-flow condition.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2001.05a
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• pp.150-153
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• 2001

In this paper, the tensile test of three kinds of the specimens was performed. Type I specimen is without notch and type II, III specimens have a radius of semi-circular edge crack of 2.5mm, 4.0mm. The tensile load(20kN and 30kN) was applied to the specimen by Universal Testing Machine. 3D-ESPI system and strain gauge measured simultaneously the strain in the center of the specimen and near the edge crack. The test results were compared with each other. Moreover, the stress concentration factor based on geometric information was calculated to confirm the accuracy of the strain measured by 3D-ESPI system. The calculated strain was compared with the measured one by 3D-ESPI system. As a result, it was confirmed that 3D-ESPI system measured the right strain near the semi-circular edge crack of the specimens.

• Journal of Korean Elementary Science Education
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• v.41 no.4
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• pp.658-672
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• 2022

The unique teaching and learning difficulties of speed-related units in elementary school science are mainly due to the student's lack of mathematical thinking ability and procedural knowledge on speed measurement, and curriculums and textbooks must be constructed with these in mind. To identify the implications of composing a new science curriculum and relevant textbooks, this study reviewed the structure and contents of the speed-related units of three curriculums from the 2007 revised curriculum to the 2015 revised curriculum and the resulting textbooks and examined their relevance in light of the literature. Results showed that the current content carries the risk of making students calculate only the speed of an object through a mechanical algorithm by memorization rather than grasp the multifaceted relation between traveled distance, duration time, and speed. Findings also highlighted the need to reorganize the curriculum and textbooks to offer students the opportunity to learn the meaning of speed step-by-step by visualizing materials such as double number lines and dealing with simple numbers that are easy to calculate and understand intuitively. In addition, this paper discussed the urgency of improving inquiry performance such as process skills by observing and measuring an actual object's movement, displaying it as a graph, and interpreting it rather than conducting data interpretation through investigation. Lastly, although the current curriculum and textbooks emphasize the connection with daily life in their application aspects, they also deal with dynamics-related content somewhat differently from kinematics, which is the main learning content of the unit. Hence, it is necessary to reorganize the contents focusing on cases related to speed so that students can grasp the concept of speed and use it in their everyday lives. With regard to the new curriculum and textbooks, this study proposes that students be provided the opportunity to systematically and deeply study core topics rather than exclude content that is difficult to learn and challenging to teach so that students realize the value of science and enjoy learning it.