• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.38-43
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• 1994

In milling process, monitoring and diagosis system is very importent to accomplish factory automation. In this study, to drvelope on-line tool breakage detection system in face milling operation, analysis and experiment were performed. The tool breakage detection experiment was performed in machining center and the effectiveness of the detection tool breakage detection alorithm and the usage of feed drive current as a detection signal were verified.

• 한국가금학회지
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• 제7권1호
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• pp.1-11
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• 1980

연중 산란수의 6-8%가 산란시부터 소비자에게 이르는 사이에 파란으로 된다. 이들 파란의 대부분은 난각의 품질과 난각파열에 영향을 준다고 판단되는 여러 가지 생물적, 환경적, 관리적 요인들과의 상호관계에 의해 발생되고 있다. 이제까지 논의된 몇 가지 파란발생 요인들을 보면 닭의 연령, 계사의 온도와 습도, 케이지 씨스템과 케이지바닥의 설계, 케이지에 사용된 재료의 종류, 1일 채란회수, 그리고 가장 중요하게 각종 기구의 원활한 작동여부와 정비상태이다. 이 중에서 닭의 연령, 유전적 체질, 환경온도, 기구의 설계와 정비유지의 양부가 파란생성에 영향하는 중요 요인이라 하겠다. 난각의 품질과 난각파열 간에는 곡선관계에 있으므로 난각질의 조그마한 차이가 파란발생빈도에는 커다란 영향을 미치게 된바. 이제까지 보고된 문헌에 의하면 파란발생 빈도는 l-2%의 낮은 수준에서 35%의 높은 수준에 이르기까지 넓은 변이를 보여주고 있다.

• 한국철도학회논문집
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• 제2권3호
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• pp.61-69
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• 1999

The durability of ballast plays an important role in track behaviour. To estimate the deterioration characteristics of ballast, several tests have been carried out by several scholars. The deterioration characteristics is very important factor in the behaviour of track and its life. In this paper, abrasion/breakage characteristics of ballast is studied to see the effect of physical ballast characteristics on ballast life. To reveal breakage characteristics of ballast, the ballast box test and the MTT field test were carried out. The breakage characteristics studied in this paper is applied to the ballast life prediction in various conditions, such as LA abrasion, annual tonnage, tamping number per year, etc

• 생명과학회지
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• 제8권1호
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• pp.67-71
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• 1998

다량의 시료를 빠르게, 적은 격비로, 간다히 검색할수 있는 예비선별법을 찾던중, ccDNA와 sulforhodamine B를 각각 사용한 미생물배양액내의 신규항암후보물질의 탐색을 시도하였다. cccDNA법으로는 3.3%가 positive 반응을 나태내었으며, SRB assat에서는 A549와 SK-OV-3에 활성을 나타내는 4개의 발효여액을 확인한수 있었다.

• 상하수도학회지
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• 제22권6호
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• pp.609-617
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• 2008

Water pipes are supposed to deliver the predetermined demand safely to a certain point in water distribution system. However, pipe burst or crack can be happened due to so many reasons such as the water hammer, natural pipe ageing, external impact force, soil condition, and various environments of pipe installation. In the present study, the reliability model which can calculate the probability of pipe breakage was developed regarding unsteady effect such as water hammer. For the reliability model, reliability function was formulated by Barlow formula. AFDA method was applied to calculate the probability of pipe breakage. It was found that the statistical distribution for internal pressure among the random variables of reliability function has a good agreement with the Gumbel distribution after unsteady analysis was performed. Using the present model, the probability of pipe breakage was quantitatively calculated according to random variables such as the pipe diameter, thickness, allowable stress, and internal pressure. Furthermore, it was found that unsteady effect significantly increases the probability of pipe breakage. If this reliability model is used for the design of water distribution system, safe and economical design can be accomplished. And it also can be effectively used for the management and maintenance of water distribution system.

• 한국축산시설환경학회지
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• 제14권1호
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• pp.47-52
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• 2008

1. 조사농장의 산란율은 하이라인, 이사브라운 모두 $85{\sim}93%$ 수준 이였으며, 농가자체 파란율은 하이라인 $1.5{\sim}2.2%$, 이사브라운 $1{\sim}1.4%$이었다. 2. 계란 이송단계별 파란발생비율은 집란벨트 4.7%> 엘리베이터 2.5%> 선란기 1.7%> 컨베이어 0.9% 순 이었다. 3. 집란벨트에서 엘리베이터로 이송 중 계란이송가이드를 설치할 경우 약 1%의 파란경감 효과가 있는 것으로 나타났다. 4. 하이라인 브라운은 주령이 높아지면서 파란율은 높아지고, 파각력은 낮아지는 것으로 나타났으며, 회귀계수 분석 유의성은 $R^2=0.7$로 파각력의 변화가 파란율에 영향을 미치는 것으로 분석되었다. 5. 이사브라운에서는 환우 전에 비하여 환우 후 파각력이 높아진 것으로 나타났다. 6. 난각 두께와 파각력, 그리고 접촉 후 파각변위와 파각력과의 관계에서 이들 함수의 변수간에 회귀관계는 유의성이 나타나지 않았다.

• KIEAE Journal
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• 제16권3호
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• pp.121-128
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• 2016

Purpose: The vacuum glazing should constantly retain the gap in vacuum state to maintain high thermal performance. To do so, pillars are used to prevent the glazing from clinging to each other by the atmospheric pressure and therefore surface of the vacuum glazing is consistently affected by residual stress. The vacuum glazing could be applied to curtain wall systems at spandrel area to fulfill a rigorous domestic standard on U-value of the external wall. However, this can lead to high glazing temperature increase by heat concentration at a back panel and finally thermal stress breakage. This study experimentally determined weakness of the vacuum glazing systems on the thermal stress breakage and investigated effect of the residual stress. Method: The experiment first built two scale-down mock-up facilities that replicate the spandrel area in curtain wall, and then installed single low-e glass and vacuum glazing respectively. The two mock-up facilities were exposed to outside to induce the thermal stress breakage. Result: The experiment showed that the temperature occurred the thermal stress breakage was $114.4^{\circ}C$ for the single low-e glass and $118.9^{\circ}C$ for the vacuum glazing respectively. The result also showed the vacuum glazing reached the critical point earlier than the single low-e glass, which means that the vacuum glazing has high potential to occur the thermal shock breakage. In addition, the small temperature difference between two glazing indicates that the residual stress scarcely affects breakage of the vacuum glazing.

• 한국환경과학회지
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• 제17권3호
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• pp.275-285
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• 2008

The floc formation, breakage and reformation of humic acid by inorganic (alum and PAC) and organic coagulants (cationic polyelectrolytes) at several conditions (pH, ionic strength and floc breakage time) were examined and compared among the coagulants at different conditions using a continuous optical monitoring method, with controlled mixing and stirring conditions. For alum, the shapes of formation, breakage and reformation curves at different pH (5 and 7) were different, but the shapes and the sizes of initial floc and reformed floc were nearly the same in the absence and presence of electrolytes at pH 7. For PAC, similar shapes of the curves were obtained at different pH and ionic strength, but the sizes were different, except for those of reformed flocs at different pH. However, for these coagulants, reformed flocs after floc breakage, occurred irreversibly for all the conditions used in this study. For organic coagulants, the time to attain the initial plateau floc size, the extent of floc strength at high shear rate and reversibility of reformed floes were different, depending floc formation mechanism. Especially, for the cationic polyelectrolyte forming humic flocs by charge neutralization or electrostatic patch effect mechanism, reformed flocs occurred reversibly, regardless of pH and floc breakage time, but occurred irreversibly in the presence of electrolytes.

• Structural Engineering and Mechanics
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• 제50권2호
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• pp.241-255
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• 2014

The girder of self-anchored suspension bridge is subjected to large compression force applied by main cables. So, serious damage of the girder due to breakage of hangers may cause collapse of the whole bridge. With the time increasing, the hangers may break suddenly for their resistance capacities decrease due to corrosion. Using nonlinear static and dynamic analysis methods and adopting 3D finite element model, the responses of a concrete self-anchored suspension bridge to sudden breakage of hangers are studied in this paper. The results show that the sudden breakage of a hanger has significant effects on tensions of the hangers next to the broken hanger, bending and torsion moments of the girder, moments of the towers and reaction forces of the bearings. The results obtained from dynamic analysis method are very different from those obtained from static analysis method. The maximum tension of hanger produced by breakage of a hanger exceeds 2.2 times of its initial value, the maximum dynamic amplification factor reaches 2.54, which is larger than the value of 2.0 recommended for cable-stayed bridge in PTI codes. If two adjacent hangers on the same side of bridge break one after another, the maximum tension of other hangers exceeds 3.0 times of its initial value. If the safety factor adopted to design hanger is too small, or the hangers have been exposed to corrosion, the bridge may collapse due to breakage of two adjacent hangers.

• 한국정보과학회논문지:정보통신
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• 제33권1호
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• pp.49-58
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• 2006

애드 흑 네트워크의 요구 기반 라우팅 프로토콜은 노드가 이동하여 경로가 손실되는 경우, 경로 유지를 위해 지역 탐색을 수행하거나 송신 노드가 새 경로 탐색을 수행하여 경로를 유지한다. 새 경로탐색이나 지역 경로 탐색을 수행할 경우, 전송중인 패킷의 지연이 발생한다. 경로 손실로 인한 지연을 줄이기 위해 경로 손실을 예측하고 대체 경로를 구성하여 경로 손실 지연을 줄이는 기법으로써 ARMP와 RPAODV가 있다. 이 라우팅 프로토콜은 링크 상태가 불안정 상태가 될 때, 지역적으로 대체 경로를 구성하여 경로 손실을 회피하는 기법으로써 대체 경로 생성의 성공률은 경로 손실과 전송 지연에 직접적인 영향을 가져온다. 본 연구에서는 이전에 제안된 경로 손실 회피 라우팅 기법들의 효율성을 검증하기 위해서 대표적인 요구 기반 라우팅 프로토콜인 AODV, 경로 손실 회피 라우팅 기법인 ARMP와 RPAODV의 수치 평가식을 제안하고, 각 프로토콜의 성능을 평가하였다. 또한, 제안한 수치 평가식의 효용성을 검증하기 위해서 컴퓨터 시뮬레이션 결과와 비교 분석한다.