• 한국건설관리학회논문집
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• 제21권3호
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• pp.11-19
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• 2020

건설업에서의 재해는 수십 년 동안 다른 산업보다 많이 발생하였기 때문에, 건설업에서의 재해는 반드시 줄여야 한다. 이러한 문제를 해결하기 위해서 작업분류체계(WBS) 및 위험분류체계(RBS)를 제시하였다. WBS와 RBS는 계층적 구조로 작업 및 위험 단위를 쉽고, 빠르게 찾을 수 있다. 그래서 본 연구에서는 건설업에서의 재해를 예방하기 위해 통합 WBS-RBS 프레임워크를 개발하고자 한다. 연구의 순서 다음과 같은 3단계로 진행되었다. ① 데이터 수집 ② 데이터 분류 ③ 통합 WBS-RBS 프레임워크 개발 순으로 진행되었다. 연구의 결과 가장 사고가 많이 발생한 건물용도, 건설공종 및 재해요인을 제시할 수 있었다. 연구 결과를 통해 의사결정자는 건물용도, 건설공종, 및 재해요인의 위험 수준을 고려할 수 있다.

• 한국진공학회지
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• 제8권1호
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• pp.36-42
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• 1999

이온빔 스퍼터링 방법으로 n-type si 기판에 고팅된, 수소를 함유하지 않은 다이아몬드성 카본 필름의 전계 방출 특성을 조사하였다. 필름의 구조나 두께에 관계없이 전계 방출 전류는 양극과 시편의 표면사이에서 발생하는 electrical breakdown에 의해 현저히 증가하였으며, 이때의 effective work function은 약 0.1eV의 작은 값을 가지고 있었다. 텅스텐 tip을 이용하여 breakdown에 의해 발생한 시편표면의 손상수위 근처를 scanning 하면서 전계 방출 전류를 측정하여, 전계 방출이 일어나는 정확한 위치를 확인하였다. 전계 방출은 breakdown에 의해 발생한 표면 손상 부위의 모든 곳에서 균일하게 일어나는 것이 아니라 특정 부위에서 집중적으로 관찰되었다. Auger electron spectroscopy와 SEM을 이용한 분석을 통해 손상 부위 중 Si과 C의 화합물이 형성된 곳에서만 절계 방출이 일어나고 있음을 알 수 있었으며, 손상부위의 형상변화는 전계 방출의 충분조건이 아니었다. 본 연구의 결과는 breakdown에 의한 전기 방출 전류의 증가는 시편 표면의 형상 변화에 의한 전계증진의 효과보다는 표면에서 발생하는 화학적 결합의 변화에 기인하고 있음을 보여준다.

• 국제학술발표논문집
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• The 10th International Conference on Construction Engineering and Project Management
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• pp.1310-1310
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• 2024

• 한국건축시공학회지
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• 제10권1호
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• pp.213-219
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• 2010

본 연구는 부산에 있는 아파트 소규모 인테리어공사 6가지 평형의 실적자료 200개를 대상으로 하여 건축공사와 소규모 인테리어공사의 분류체계를 비교하고, 일반적인 소규모 인테리어공사의 공종별 공사비를 분석하였다. 본 연구에서 도출된 결과는 다음과 같다. (1) 아파트 소규모 인테리어공사비는 1,000~1,500만원 범위인 79.2M2(24PY)과 105.6M2(32PY)에 대해서 주로 이루어지므로 이러한 2가지 평형에 대한 자재비, 노무비에 대한 심층적인 원가분석이 필요하다. (2) 아파트 소규모 인테리어공사는 일반적인 건축공사의 분류체계와 다르게 마감공사가 주로 진행되므로 건축공사표준시방서의 22개의 대분류와는 다른 9개의 분류체계로 구분하여 적용하는 것이 타당하다. (3) 소규모 인테리어공사의 각각의 평형별 평균공사금액과 공종보할을 검토한 결과, 24평형(24PY)의 평균공사금액은 약 1,050만원이고 공종별 보할은 금속공사 12.8%, 수장공사 17.8%, 화장실공사 19.7%로 분석되었으며, 싱크 가구공사가 22.1%로 가장 높은 보할을 나타내었다. 또한, 32평형의 평균공사금액은 약 1,250만원이며, 공종별 공사보할은 수장공사가 28.6%로 가장 높게 나타났으며, 28평형이상에서는 수장공사의 공종보할이 가장 큰 것으로 분석되었다.

• 한국BIM학회 논문집
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• 제11권2호
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• pp.1-16
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• 2021

Since entering the 21st century, the construction industry has developed faster and faster, and more and more technologies have been applied in the construction industry. BIM technology (Building Information Modeling) was born in this environment. The application of BIM technology can greatly improve the efficiency of cost management and help achieve the goal of cost management. But through BIM to realize project cost management, there is still no good solution. In order to solve this problem, this paper puts forward the concept of WBS structure applied to construction projects by studying the BoQ (Bill of Quantities) list based on BIM, and proposes the numbering method of the structure. The WBS (Work Breakdown Structure) structure proposed in this paper divides more than 5000 cost objects into 133 projects according to the type of work and project schedule. This structure helps to realize the application of BIM in project cost management. Although this article has studied more than 5000 data of three projects, it does not think that it can cover all cost objects in the existing construction industry. The purpose of this article is to propose a solution for cost and Process Control using BIM-based BoQ data.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 기술교육위원회 창립총회 및 학술대회 의료기기전시회
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• pp.67-71
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• 2001

PT of epoxy mold type have tendency to occur dielectric breakdown in high voltage system. These are using for measurement of voltage or protection of system and application voltage is 25.8kV. Therefore, for improving a lots of problems like as partial discharge, we had analyze on the destroyed Epoxy molded type PT and processing of production. As a results, we concluded that the reason of dielectric breakdown was defect of processing and degradation of insulation by electrical stress. In this work, We presented a method of solution in processing of production. which is reduction of the PO which was occurred at the insulation material. so we must many try to remove faults, these problems are mainly to winding methods of 1st coil. the other side, Reformation of 1st coil improved property of PD and we could prove it with experiments.

• 비파괴검사학회지
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• 제27권6호
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• pp.541-549
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• 2007

This work describes an investigation into the feasibility of using an acoustic emission (AE) technique to evaluate the integrity of a composite actuator with a PZT ceramic under electromechanical cyclic loading. AE characteristics have been analyzed in terms of the behavior of the AE count rate and signal waveform in association with the performance degradation of the composite actuator during the cyclic tests. The results showed that the fatigue cracking of the composite actuator with a PZT ceramic occurred only in the PZT ceramic layer, and that the performance degradation caused by the fatigue damage varied immensely depending on the existence of a protecting composite bottom layer. We confirmed the correlations between the fatigue damage mechanisms and AE signal types for the actuators that exhibited multiple modes of fatigue damage; transgranular micro damage, intergranular fatigue cracking, and breakdown by a short circuiting were related to a burst type signal showing a shortly rising and slowly decaying waveform with a comparably low voltage, a continuous type signal showing a gradual rising and slowly decaying waveform with a very high voltage and a burst and continuous type signal with a high voltage, respectively. Results from the present work showed that the evolution of fatigue damage in the composite actuator with a PZT ceramic can be nondestructively identified via in situ AE monitoring and microscopic observations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1081-1084
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• 1995

Internal voids located within an insulation will arise partial discharge that causes local breakdown and even the entire insulation breakdown. For HV apparatuses, it is usual case that several voids are formed within non-uniform electric field condition rather than single void within uniform field, which can be solved analitically. The purpose of this work is to study partial discharge and breakdown characteristics of an insulation according to the distribution pattern of two disc-type voids that are located within non-uniform field. The results from numerical field analysis and experiments show that the electric field within the voids decreases as they are arranged more serially, which accordingly results in the increase of partial discharge inception field(PDIF) much higher than that of single void model. With parallel arranged voids, PDIF is almost the same as that of single void model. On the other hand, AC breakdown strength decreases as voids are arranged more serially, which is a natural result considering the reduction of effective insulation thickness. For parallel voids, this effect cannot he noticed where as they show different pattern compared with single void and serial void models in $\Phi$-Q-N analysis. Considering these results may leads us to the conclusion that, in the evaluation of insulating products through PD test, it is not sufficient to determine only PDIV or existence of PD at predetermined voltage level. We could evaluate more accurately by considering all the available data such as PDIV, PD magnitude, PD occurring phase, number of PD pulses, and etc.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.490-493
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• 2004

The purpose of this study is to construct technology product concept a deployment model on seeds type R&D projects. For this purpose, we have peformed the following studies : First, technology opportunities and market opportunities through ${\ulcorner}$perception analysis${\lrcorner}$ are captured by perceptional structure of technology experts and customers on the existing technologies and products. Second, the optimal technology product concept deployed by ${\ulcorner}$SAT(System Alternatives Tree)${\lrcorner}$ has been constructed by the ${\ulcorner}$PWBS(Project work Breakdown structure)${\lrcorner}$.

• 한국기계가공학회지
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• 제16권4호
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• pp.38-45
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• 2017

A finite element analysis-based approach which investigates the causes of the breakdown in the outer ring of the choke at hot rod rolling mill is presented. Two-dimensional drawings of the whole vertical-type mill stand are transformed into three-dimensional CAD models. Non-linear elasto-plastic deformation analysis of material at the roll gap is performed for computing roll force and torque of the work roll. Then, the reaction forces of the bearing rings together with a set of roller bearings that support the work roll are obtained by means of rigid body motion analysis. Finally, stress behaviors in the bearing rings together with a set of roller bearings that support the work roll are investigated by linear elastic analysis. Results reveal that stress at the contact area between the outer ring and roller bearing is extraordinary high when an internal gap between an external surface of the outer ring and the internal surface of the chock due to wear of the inside of the chock occurs.