• Magazine of the Korean Society of Agricultural Engineers
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• v.7 no.1
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• pp.843-849
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• 1965

Some simple devices to demonstrate important hydraulic principles to students are necessitated in fluid mechanics or hydraulics classes. These devices should\ulcorner be easy to make and operate with inexpensive cost. The writer has studied some simple demonstrhation apparatus of hydraulic principles which were made with cheap materials. The purpose of this paper is to present the results of the study. In this paper, hydraulic principles that can be demonstrated by using these apparatus are described, the plans of them are presented, and how to make them and what materiaIs to be used are briefly explained. An axial-flow fan is a device with which the flow of air is supplied for several purposes. It consists of a duct, a fan and a guide vane. It may be possible to demonstrate the principles of propeIler,drag force, lift, etc.

• Proceedings of the KIPE Conference
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• 2012.07a
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• pp.617-618
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• 2012

Recently as the inactive response characteristics of the existing RCD(Residual Current protective Device) used on low voltage power distribution system, so control of overload and electric short circuit faults, major causes of electrical fires, are not enough. Therefore, this paper is proposed a prevention apparatus using neutral line voltage and semiconductor switching devices for the prevention of electrical disasters in low voltage power distribution system caused by overload or electric short circuit faults. The proposed prevention apparatus confirms the excellent characteristics in response velocity and accuracy in comparison with the conventional circuit breaker(RCD) through various operation performance analysis.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.11
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• pp.1626-1630
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• 2015

This paper reflected the Temperature test value and compare the Computational Fluid Dynamic analysis value on particular characteristics of the multi-winding transformer's cooling apparatus equipped by heat pipe with excellent heat transfer ability on design Particularly if you look at multi-winding transformers that supply high-quality Direct current power to silicon production apparatus, heat generation due to high current supply is excessive thus, an innovative cooling apparatus is required in particular for reduced size transformer.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.07a
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• pp.481-484
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• 2004

A form of measured temperature distribution to estimate condition of a electrical apparatus is a absolute reference for condition of the apparatus, time rate of transition, and difference between reference and currently temperature. Because passive thermography which has not injection of external thermal stimulation shows difference of temperature being on surface of a structure and temperature difference between the structure and back ground, the result could apply only to estimation or monitor for condition of terminal relaxation and overload related with temperature rising. However, a thermal flow in active thermography is differently generated by structure and condition of surface and subsurface. This paper presents the nondestructive testing using the properties and includes the results by heat injection and cooling to the apparatus. The buried discontinuity of subsurface could be detected by these techniques.

• Journal of Advanced Engineering and Technology
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• v.11 no.4
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• pp.259-265
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• 2018

In this paper, we propose a test method to evaluate the reliability of the recliner sofa in the early stage of production. In order to develop the test method, we analyzed the failure mechanism occurring in the field and designed the performance test, environmental test, accelerated life test methods based on the analysis of failure mechanism. The failure mechanism is reproduced by applying the designed test. The reliability of the recliner sofa can be verified at the production stage through the proposed test method.

• Journal of the Korean Society of Safety
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• v.33 no.6
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• pp.123-127
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• 2018

Recent catastrophic accidents at the underground subway stations in South Korea have proven that the subway evacuation is an important safety concern. Previous studies have used commercial programs for safety assessment or have been focused on development of computing algorithms rather than the basic analysis data which form the foundation of studies. In this study, we designed a new movement recording apparatus which measured and analyzed crowd movements including but not limited to moving velocity, specific flow rate and crowd density. Moreover, We propose new effective analysis method for evacuation studies with this apparatus.

• Korean Journal of Pharmacognosy
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• v.52 no.3
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• pp.157-162
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• 2021

The heat-mediated reflux apparatus extraction of Paeonia lactiflora Pall. has been widely used as a traditional extraction method. In this paper, the microwave apparatus extraction method of Paeonia Radix was performed and the active ingredients and functional constituents were compared with the reference extraction method. The most effective extraction condition of albiflorin using the microwave was 120℃ in 50% methanol, and paeoniflorin was maximally extracted at 60℃. The reduced level of paeoniflorin molecule at high-pressure and high-temperature extraction condition was caused by the molecular instability. Additionally, the microwave extraction of 50% methanol extracts at 150℃ showed the highest functional constituents determined by in vitro DPPH radical scavenging activity, polyphenol concentration, and tyrosinase inhibition assay. The microwave apparatus was adapted as a rapid, low-cost, and environmentally friendly method to extract active ingredients and the practical extraction conditions of Paeonia Radix can be used in industrial applications.

• Journal of Sensor Science and Technology
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• v.30 no.1
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• pp.10-14
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• 2021

Wet etching is more economical than dry etching and provides a uniform etching depth regardless of wafer sizes. Typically, potassium hydroxide (KOH) and tetra-methyl-ammonium hydroxide (TMAH) solutions are widely used for the wet etching of silicon. However, there is a limit to the wet etching process when a material deposited on an unetched surface reacts with an etching solution. To solve this problem, in this study, an apparatus was designed and manufactured to physically block the inflow of etchants on the surface using a rubber O-ring. The proposed apparatus includes a heater and a temperature controller to maintain a constant temperature during etching, and the hydrostatic pressure of the etchant is considered for the thin film structure. A corrugation membrane with a diameter of 800 ㎛, thickness of 600 nm, and corrugation depth of 3 ㎛ with two corrugations was successfully fabricated using the prepared device.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.208-209
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• 2021

In 2017, 100 aftershocks with a magnitude of 2.0~3.0 and 615 minor earthquakes in Pohang in Korea caused the collapse and destruction of aggregate, tile, glass, and other structural components of multi-family houses constructed as finishing materials for buildings, causing damage to vehicles and casualties. Based on this factor, seismic design standards were established for non-structural elements of buildings that were applied only to past structures. Therefore, this study reinterpreted various vibration response spectra transmitted to waterproof layers as well as the definition and concept of the waterproof layer demand response spectrum derived by developing various vibration response test evaluation devices through a new testing apparatus.

• Journal of Sasang Constitutional Medicine
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• v.18 no.2
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• pp.41-49
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• 2006

1. Objectives The Face is an important standard for the classification of Sasang Contitutions. We are developing 3D Face Automatic Recognition Apparatus to analyse the facial characteristics. So We should examine a shape demobilization error of 3D Face Automatic Recognition Apparatus. 2. Methods We compared facial shape data be demobilized by 3D Face Automatic Recognition Apparatus with facial shape data that be demobilized by 3D laser scanner. The subject was two korean men. And We analysed the average error and the maximum error of two data. In this process, We used one datum point(the peak of nose) and two datum line(vertical section and horizontal section). 3. Results and Conclusions In each this comparison, the average error of vertical section was 1.962574mm and 2.703814mm. and the maximum error of vertical section was 16.968249mm and 18.61464mm. the average error of horizontal section was 4.173203mm and 21.487479mm. and the maximum error of horizontal section was 3.571210mm and 17.13255mm. Also We complemented this apparatus a little and We reexamined a shape demobilization error of 3D Face Automatic Recognition Apparatus again. Accuracy of a shape demobilization was improved a little. From now on We complement accuracy of a shape demobilization in 3D Face Recognition Apparatus.