• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 추계학술대회
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• pp.189-195
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• 2004

It compared quality characteristics for the stone surface treatment system and its products. With the result, the flame burner equipment was mainly used to the surface treatment of granite, but it occurred greatly the high temperature, the rock fragment, the noise and dust. For the other side, the whetstone polishing machine for the polishing was a maintenance for the specific physical properties of stone, and it did not occur the stone fragment and the dust. The durability of the stone products due to the flame burner was investigated with that it falls to $20\sim25\%$ more than the surface treatment by the whetstone polishing. Share's hardness of the polishing products in the durability test showed more greatly index than the flame burner and conventional product. The polishing products of Pochon stone in the case of the abrasion resistance showed great more $15\%$ than the general products, more $9\%$ than the products by the flame burner.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 춘계학술대회 발표 논문집
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• pp.163-168
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• 2004

Linear motor can directly apply to the system needed linear mot ions without rotary mot ions. To control a high-speed and high-resolution, the development of the linear motors is recently required in the high-integrated and speed process industry. This paper presents vibration analyses as well as measurement standards of the newly developed linear motors through analyzing the vibration characteristics and thermal behaviors of the advanced products. Vibration experiments are conducted for identifying the hysteresis and vibration level during operation. They are also included in the modal test to analyze the vibration. Analytic data using Finite Element Method (FEM) are compared with the results of the modal. Loss of temperature generated the linear motor leads to a serious deformation within its parts. The thermal behaviors are very important factor in linear motor. The FEM and experiments make it possible to understand these characteristics.

• 연구논문집
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• 통권31호
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• pp.149-156
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• 2001

Hydrogen damage affects carbon steel tubes in many fossil-fuel-fired boilers, often causing large tube ruptures that necessitate an immediate shutdown. Therefore, equipment handling high-temperature, high-pressure hydrogen must undergo careful periodic inspection because of its susceptibility to hydrogen attack. This paper describes the application of an ultrasonic technique for detecting the presence of hydrogen damage in utility boiler tubes. The accuracy of the technique has been shown in laboratory tests. However, it is difficult to evaluate hydrogen attack quantitatively by this technique, because ultrasonic wave is influenced by the test conditions and the material itself.

• 한국전자통신학회논문지
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• 제18권6호
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• pp.1337-1344
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• 2023

고주파 전기 수술 장비와 함께 사용되는 수중 치료용 고주파 전극 프로브에 대한 성능 평가 및 신뢰성 평가에 대한 안전성을 확보에 필요한 고주파 전극 프로브 개발 및 평가 시험방법 개발, 평가 모의시험 장치 개발하여 성능 안전성 확보에 필요한 성능 평가 효과를 알아보고자 한다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2006년도 제26회 춘계학술대회논문집
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• pp.100-109
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• 2006

구리합금을 연소실 내벽으로 사용하고 탄화수소계 연료를 추진제로 사용하는 재생냉각 연소기에서 냉각채널 벽면온도가 상승함에 따라 냉각채널에 반응물이 침착되는 코킹현상이 일어난다. 이러한 현상은 냉각채널을 흐르는 연료에 의한 냉각효과를 감소시키게 되고, 높은 열유속으로 운영되는 연소기 내부벽면을 과열시켜 손상에 이르게 한다. 본 논문에서는 구성된 전기가열장치에 대해 소개하고 연소실 재질로 사용되고 있는 구리합금과 추진제로 사용되는 탄화수소계 연료 Jet A-1에 대해 가열시험 결과를 제시한다. 시험결과에 따라 각 조건에서의 구리합금과 Jet A-1의 적합성을 평가하였다.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 춘계학술대회논문집
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• pp.440-443
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• 2008

Plume radiation has been measured during ground tests of KSLV-I kick motor in order to predict the thermal load on the equipment around the kick motor at flight. The measuring positions are the kick motor base, and the measured heats were about 2${\sim}$5 w/cm$^2$. The measured heat showed a lot of shot fluctuation in their values, and the radiative heats at the latter half of time are higher than those of the first half. A plausible explanation for these phenomena was given as the variation of alumina particles with time. The radiative heats along the plume axis were also measured recently at 8 positions with 1.5m radius from plume axis, but only the initial parts of the results could be acceptable because the sensor were damaged by the accumulated heat. The strongest heat occurred at the middle of the plume, which can be explained with different view factors. Despite of the plausible explanation, it seems to need more analysis because the plume structure such as temperature, alumina particle, after burning has not been revealed until yet. The measure heat flux has been reflected in the prediction of the plume radiation at high altitude where the kick motor operates.

• 한국항공우주학회지
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• 제39권4호
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• pp.378-384
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• 2011

나로호 비행시험 동안 화염의 특성과 이로 인한 발사대의 영향을 측정하기 위해서 발사패드 및 화염유도로에 다양한 센서들을 설치하였고, 파라미터 측정시스템은 이러한 비행시험 데이터를 수집을 담당하고 있다. 측정 시스템 구성과 센서 위치 및 데이터 수집절차와 같은 측정 방법론을 논문에 기술하였다. 그리고 본 논문에서는 1차와 2차 비행 시험 데이터를 비교하였고, 측정 데이터 특성에 대해서 설명하였다.

• 대한기계학회논문집B
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• 제29권1호
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• pp.151-158
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• 2005

A characteristic of discharge for a foam spray nozzle with various parameters was investigated. The discharge patterns from a fire foam spray nozzle are important to evenly spray over a maximum possible floor area. Two parameters of a foam spray nozzle were chosen, and compared with those from the standard one. Also, in order to evaluate the performance of discharged foam agents used to protect structures from heat and fire damages, the thermal characteristics of fire-protection foams were experimentally investigated. A simple repeatable test for fire-protection foams subjected to fire radiation was developed. This test involves foam generation equipment, a fire source for heat generation, and data acquisition techniques. Results show that the bubble size of foam is increased by large inside diameter of orifice or closed air hole, but phenomenon of discharge angle and expansion ratio is opposite. For the case of the open air hole, liquid film of a circular cone discharges with formation, growth, split and fine grain. In case of the closed air hole, a pillar of foam solution discharges with that. Though the temperature gradient in the foam increases with increased foam expansion ratio. it is not change with increased intensity of heat flux.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권4호
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• pp.1193-1215
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• 2021

The measurement of the key product quality index plays an important role in improving the production efficiency and ensuring the safety of the enterprise. Since the actual working conditions and parameters will inevitably change to some extent with time, such as drift of working point, wear of equipment and temperature change, etc., these will lead to the degradation of the quality variable prediction model. To deal with this problem, the selective integrated moving windows based principal component regression (SIMV-PCR) is proposed in this study. In the algorithm of traditional moving window, only the latest local process information is used, and the global process information will not be enough. In order to make full use of the process information contained in the past windows, a set of local models with differences are selected through hypothesis testing theory. The significance levels of both T - test and χ² - test are used to judge whether there is identity between two local models. Then the models are integrated by Bayesian quality estimation to improve the accuracy of quality variable prediction. The effectiveness of the proposed adaptive soft measurement method is verified by a numerical example and a practical industrial process.

• 생물환경조절학회지
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• 제26권4호
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• pp.242-248
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• 2017

작업 편이성을 높일 수 있는 원통형 종이포트를 일정한 크기로 생산하여 연속적 공급이 가능한 원통형 종이포트 제조장치를 개발하고, 장치의 성능시험을 수행하였다. 원통형 종이포트 제조장치는 상토공급부, 종이 공급부, 종이 접착부, 종이포트 절단부로 구성되어 종이포트제조를 위한 상토공급부터 종이포트 절단까지의 공정이 연속적으로 이루어지도록 하였다. 상토 함수율에 따른 적정 상토공급압력시험에서는 상토를 공급하는 진공압이 높을수록 종이포트의 경도와 가밀도가 높게 나타났으며, 수분 함수율이 높아질수록 경도와 가밀도는 증가하다가 낮아지는 경향을 나타내어 포트제조부로 상토를 공급하기 위한 적정 함수율 및 공기압은 50%~60%와 0.5 Mpa인 것으로 판단된다. 제조장치의 성능과 고형접착제에 의한 종이 접착시간을 고려하였을 때, 종이의 원통성형이 이루어지고 가이드부와의 유착없이 연속적인 공정이 이루어질 수 있는 적정 온도는 $150^{\circ}C^{\sim}160^{\circ}C$인 것으로 판단된다. 원통형 종이포트 절단칼날의 최적 절단각도를 구명하기 위한 시험에서는 절단 속도와 작업의 안전성을 고려하여 최소 기울기인 $30^{\circ}$에서 깨끗한 단면을 나타내는 일자칼날을 사용하는 것이 적합할 것으로 판단된다. 원통형 종이포트 제조장치의 성능시험에서 종이포트의 길이는 설정한 길이로 균일하게 제조되었으며, 종이접착 및 상토공급 등 준비 시간을 제외한 종이포트(직경: 40mm, 길이: 40mm) 제조 작업성능은 3300개/hr로 나타났다.