• Journal of Power System Engineering
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• v.11 no.2
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• pp.72-76
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• 2007

Since the magnetic bearing system has unstability inherently it is necessary to measure the displacement for stable operation. Normally the displacement measurement is implemented by using sensors. The sensor for the displacement measurement is selected by precision, installation space, effect of magnetic field and response speed. And the cost of displacement measurement sensor also is considered. At the cost the hall effect sensor has a large advantage comparing with the others. Therefore this study concern about the basis experimental test for the displacement measurement of the magnetic bearing system that uses the hall effect sensor coupled with a tiny permanent magnet. The experimental results confirm the validity and practicability for this displacement measurement sensor.

• Transactions of the Korean hydrogen and new energy society
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• v.32 no.6
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• pp.642-648
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• 2021

In this paper, an experimental study was conducted on the performance of the cooling tower. In order to improve reliability in the cooling tower performance test, the measurement uncertainty of the instrument was estimated. Measurement uncertainty refers to the uncertainty of a measurement, estimates the range in which the expected value of the measurement can be within a certain confidence level, and suggests a range in which the measured representative value is incorrect. Therefore, the measurement result of the performance experiment is not an actual value, but a reasonable estimated value. The measurement uncertainty for the test was calculated and the measured results were presented.

• Smart Structures and Systems
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• v.30 no.3
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• pp.287-301
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• 2022

The machine-vision based structural displacement measurement methods are widely used due to its flexible deployment and non-contact measurement characteristics. The accuracy of vision measurement is directly related to the image resolution. In the field of computer vision, super-resolution reconstruction is an emerging method to improve image resolution. Particularly, the deep-learning based image super-resolution methods have shown great potential for improving image resolution and thus the machine-vision based measurement. In this article, we firstly review the latest progress of several deep learning based super-resolution models, together with the public benchmark datasets and the performance evaluation index. Secondly, we construct a binocular visual measurement platform to measure the distances of the adjacent corners on a chessboard that is universally used as a target when measuring the structure displacement via machine-vision based approaches. And then, several typical deep learning based super resolution algorithms are employed to improve the visual measurement performance. Experimental results show that super-resolution reconstruction technology can improve the accuracy of distance measurement of adjacent corners. According to the experimental results, one can find that the measurement accuracy improvement of the super resolution algorithms is not consistent with the existing quantitative performance evaluation index. Lastly, the current challenges and future trends of super resolution algorithms for visual measurement applications are pointed out.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.19 no.1
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• pp.7-14
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• 2011

In this study, the measurement uncertainty of combustion experimental system and experimental parameters for hybrid rocket were evaluated by B type evaluation method. The measurement uncertainty of all experimental parameters was lower than 3%. The highest value of expanded uncertainty was characteristic velocity efficiency with 2.83% and the expanded uncertainty of regression rate which is the design and performance parameter was indicated to 0.03%. These results shown that the reliability of hybrid combustion system was located within allowed limits.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1109-1114
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• 2003

The initial crack often occurs on the bonded interface and it is the general cause of the interface fracture. It is very significant to establish the measurement method of interfacial crack by applying the ultrasonic technology into the interface of bonded dissimilar materials. In this paper, the interfacial crack length was measured by ultrasonic attenuation coefficient in the Al/Epoxy bonded dissimilar materials of double-cantilever beam(DCB). The energy release rate, G, was obtained by the experimental and Ripling's equation measurement of compliance. The experimental results represent that the relation between interfacial crack length for the ultrasonic attenuation coefficient and energy release rate is increased proportionally. From the experimental results, a measurement method of the interfacial crack length by the ultrasonic attenuation coefficient was proposed and discussed.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.18 no.3
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• pp.44-54
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• 2005

Background and Objectives: Allergic contact dermatitis is a common environmental health issue and seriously affect the patient's quality of life. The more our environment industrialized, the number of material that could cause the allergic contact dermatitis has been increased, consequently the prevalence of allergic contact dermatitis has been increased. In oriental medicine, clinically Chogam-Tang has been used fur the treatment of allergic dermatitis, eczema, atopic dermatitis etc. The objective of this study is to investigate the effects of Chogam-Tang on allergic contact dermatitis Meterial and Methods: Fifteen Sprague-Dawley rats were divided into three groups: normal, control, experimental group. Control and experimental group were induced allergic contact dermatitis, by DNCB. Experimental group was orally administered the Chogam-Tang. Each group was observed after 24, 48 and 72 hours. Contact hypersensitivity assay, melanin-erythema measurement, pH measurement skin moisture measurement and biopsy were performed. Results: 1. In contact hypersensitivity assay, experimental group showed decreased ear swelling compared with control group at 48hours. 2. ln melanin measurement there was no difference in three groups. 3. In erythema measurement experimental group showed reduction at 48. 72 hours. 4. In pH measurement, experimental group and control group showed increase in pH but there was no statistical significance. 5. In skin moisture measurement, experimental group showed higher skin moisture level than control group at 24 hours and showed lower skin moisture level at 72 hours, but there was no statistical significance. 6. In biopsy, experimental group showed decrement of Iymphocyte as time goes by, and regeneration of keratin layer was increased compared with normal group. Conclusions: Chogam-Tang shows anti-inflammatory effect in biopsy, improves hydration levels of skin, decreases erythema level on allergic contact dermatitis.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.1318-1321
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• 1997

A method for two-dimensional position measurement using an enclosing field has been studied and reported. The feature of this mehtod is zooming functional measurement by operating both the initial phase shift and the brightness ratio of the lighting function. An experimental system was developed and the experimental results on zooming effects are shown in this paper. This system is also an example of a "progressive learning measurement system".tem".uot;.

• Journal of electromagnetic engineering and science
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• v.15 no.4
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• pp.250-257
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• 2015

This paper presents an experimental measurement system for 3-6 GHz microwave tomography (MT) of the breast. The measurement system is constructed as a minimal test bed to verify key components such as the sensing antennas, radio frequency (RF) transceiver, sensing mechanism, and image reconstruction method for our advanced MT system detecting breast cancer at an early stage. The test bed has eight RF channels operating at 3 to 6 GHz for high spatial resolution and a two-axis scanning mechanism for three-dimensional measurement. The measurement results from the test bed are shown and discussed.

• Transactions of the Korean hydrogen and new energy society
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• v.33 no.6
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• pp.838-844
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• 2022

In this paper, an experimental study was conducted on the energy efficiency ratio of performance for air source heat pump. The energy efficiency ratio presents the operating efficiency of heat pump performance. In order to improve reliability in the energy efficiency ratio test of air source heat pump, the measurement uncertainty of the instrument was estimated. Measurement uncertainty refers to the uncertainty of a measurement, estimates the range in which the expected value of the measurement can be within a certain confidence level, and suggests a range in which the measured representative value is incorrect. The measurement uncertainty for the energy efficiency ratio test of air source heat pump was calculated and the measured results were presented.

• Journal of KSNVE
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• v.2 no.3
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• pp.181-192
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• 1992

A method of measuring the transmission loss of silencer using two microphone technique is described. Two microphone methol is used to elliminate the measurement error due to reflected wave spectra in inlet/outlet duct of silencer. Errors associated with the measurement method are studied. Henceforth the methods to effectively supress the influence are presented. Based on these considertions, the appropriate procedure of experimental set-up to measure the transmission loss a silencer is described with experimental verifications.