• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1252-1252
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• 2022

Temporary work that utilizes temporary equipment (e.g., system scaffold and system pipe support) in construction work is one of the most vulnerable work from a safety perspective in South Korea. Typically, temporary equipment is reused at construction sites. The Korea Occupational Safety and Health Agency announced guidelines regarding the performance standards for reusable temporary equipment to prevent the accidental collapse of temporary facilities. Nevertheless, temporary facilities' collapse still occurs, which could be attributed to a degradation in the performance due to the reuse of temporary equipment. Therefore, this study investigated the performance of simple temporary structures assembled with new and reused equipment. To this end, an experimental module was designed based on previous research cases, and two experimental models were constructed, in which one was assembled using new equipment (Model A), and the other was built using reused equipment (Model B). To determine the performance of each model, a load test was conducted to measure the maximum load that each model could withstand. The experimental results revealed that the maximum load of Model B was 15% lower than that of Model A. This indicates that there is a meaningful performance difference between those two models. Based on this result, the authors decided to perform additional tests with more realistic models than previous ones. The new experimental module was designed to ensure compliance with the Korean design guidelines. In this presentation, the authors show details of the first tests and their results and plan for the additional test.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.284-285
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• 2008

For development of low fuel consumption vehicle, design of engine can he changed and it brings collateral effect. Abnormal vibration is one of bad effect of high efficiency engine and it can be got over by active engine mount system. For development of active engine mount system, an adequate experimental equipment is required which contain characteristic of real engine movement. To make adequate experimental equipment, regulated force vibrating system including characteristics of vehicle chassis is required.

• 대한공업교육학회지
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• 제45권2호
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• pp.1-20
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• 2020

이 연구의 목적은 화학공업을 공부하는 학생들이 액위제어를 쉽게 이해할 수 있도록 하기 위해, 조립형 액위제어 실험장치를 제작하고 이를 수업에 적용할 수 있는 체험활동과제를 개발하는 것이다. 이를 위해 2015 개정 교육과정 화학공업 실무과목에서 액위제어와 관련된 내용요소를 분석하여, 조립형 액위제어 실험장치를 활용하는 체험 활동과제를 개발하여 전문가 검증을 마친 후, 16차시의 체험활동과제를 S 마이스터고등학교 학생 19명에게 적용하였다. 이 연구에서 얻은 결과는 다음과 같다. 첫째, 기존 완성형 액위제어 실험장치를 분석하고, 이를 토대로 학생 수준에서 조립 가능하며 실습에 활용할 수 있는 새로운 조립형 액위제어 실험장치를 설계·제작하였다. 둘째. 2015 개정 교육과정의 NCS기반 '화학공정유지운영' 실무과목의 내용을 분석하여 액위제어와 관련된 학습 내용들을 추출하였다. 이 액위제어 관련 내용 중에서 공정 흐름도의 이해, 액위제어 실험장치 제작, 유량 측정, 액위제어 현상 확인 등의 실습을 위 조립형 액위제어 실험장치로 진행하여 액위제어 관련 내용을 체계적으로 학습할 수 있도록 하였다.

• Ocean Systems Engineering
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• 제10권2호
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• pp.163-179
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• 2020

Considering the huge demand of several types of subsea equipment, as Christmas Trees, PLEMs (Pipeline End Manifolds), PLETs (Pipeline End Terminations) and manifolds for instance, a critical phase is its installation, especially when the equipment goes down through the water, crossing the splash zone. In this phase, the equipment is subject to slamming loads, which can induce impulsive loads in the installation wires and lead to their rupture. Slamming loads assessment formulation can be found in many references, like the Recommended Practice RP-N103 from DNV-GL (2011), a useful guide to evaluate installation loads. Regarding to the slamming loads, RP-N103 adopt some simplifying assumptions, as considering small dimensions for the equipment in relation to wave length, in order to estimate the slamming coefficient C_S used in load estimation. In this article, an experimental investigation based on typical subsea structure dimensions was performed to assess the slamming coefficient evaluation, considering a more specific scenario in terms of application, and some reduction of the slamming coefficient is achieved for higher velocities, with positive impact on operability.

• 한국화재소방학회논문지
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• 제28권2호
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• pp.14-19
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• 2014

현재 국내의 침윤소화약제 기술기준은 표면장력에 대한 기준만 존재하여 이를 통한 약제의 성능평가는 어려운 실정이다. 따라서 침윤소화약제의 성능평가 기법을 제시하기 위해 축소모형 실험 장치를 통한 최적화된 성능평가 방법을 제시하고자 한다. 본 연구는 해외 기준인 NFPA 18의 실험과 자체 제작된 축소모형 실험 장치를 이용한 실험의 결과 비교분석을 통해 자체 제작 축소모형 실험 장치실험 결과의 타당성을 규명하고자 한다. 목화솜을 대상으로 침투성능만을 평가하는 NFPA 18 실험과 목분을 대상으로 침투성능과 소화성능을 모두 평가하는 축소모형 실험을 비교분석한 결과 NFPA 18의 실험과 자체 제작 축소모형 실험에서 모두 소화용수의 침투성에 관한 변별력을 확인할 수 있었다. 또한 자체 제작 축소모형 실험에서는 T/C를 통한 내부온도 측정을 통해 보다 명확한 변별력을 나타냄을 확인하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.802-805
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• 2007

The exhaust system, including a muffler, is one of the major sources to generate the radiated noise of construction equipment. The muffler is generally known that it reduces the exhaust noise level, but it sometimes increases the noise level because of the flow effect inside a muffler. So, it is required to consider the flow effect inside a muffler to reduce the exhaust noise level of construction equipment. In this paper, an experimental method to consider a quantitative flow effect inside a muffler was set up through a series of tests. Finally, the experimental result was verified through the flow noise analysis using CFD analysis result. These results make it possible to understand the dynamic characteristics of the flow noise and to design the low noise muffler for the construction equipment.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.291-298
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• 2000

This paper describes a theoretical and experimental investigation into an active vibration isolation system in which four electromagnetic actuators are installed in parallel with each of four passive mounts placed between a piece of equipment and a vibrating base structure. Decentralised velocity feedback control is employed, where each actuator is operated independently by feeding back the absolute equipment velocity at the same location. Although one end of each actuator acts at the sensor positions on the equipment, the control system is not collocated because of the reactive forces acting on the flexible base structure, whose dynamics are strongly coupled with the mounted equipment. Isolation of low frequency vibration is considered where the equipment can be modelled as a rigid body and the mounts as lumped parameter springs and dampers. Control mechanisms are discussed, and some experimental and simulation results are reported.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2003년도 추계 학술발표회논문집
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• pp.403-410
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• 2003

This paper presents the results of experimental studies on the equipment isolation effect in the nuclear containment. For this purpose, shaking table tests were performed. The isolation system, known as Friction Pendulum System (FPS), combines the concepts of sliding bearings and pendulum motion was selected. Peak ground acceleration, bidirectional motion, effect of vertical motion and frequency contents of selected earthquake motions were considered. Finally, it is presented that the FPS systems are effective for the small equipment isolation. Key word equipment isolation, nuclear containment, shaking table test, Friction Pendulum System (FPS)

• 한국재료학회지
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• 제25권6호
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• pp.305-316
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• 2015

The study of grinding behavior characteristics on the metal powders has recently gained scientific interest due to their useful applications to enhance advanced nano materials and components. This could significantly improve the property of new mechatronics integrated materials and components. So, a new evaluation method for standardizing grinding equipment and a comparative study for the grinding experiment during the grinding process with various grinding mills were investigated. The series of grinding experiments were carried out by a traditional ball mill, stirred ball mill, and planetary ball mill with various experimental conditions. The relationship between the standardization of equipment and experimental results showed very significant conclusions. Furthermore, the comparative study on the grinding experiment, which investigated changes in particle size, particle morphology, and crystal structure of materials with changes in experimental conditions for grinding equipment, found that the value of particle size distribution is related to the various experimental conditions as a revolution speed of grinding mill and media size.

• 한국초등과학교육학회지:초등과학교육
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• 제27권3호
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• pp.244-251
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• 2008

One of the problems with testing for the presence of $CO_2$ is that the results are not visible. In order to over-come this weak point, a new testing method was developed with BTB indicator equipment, that made the gas visible. After that, the experiment was performed and tested the effects of the new visible equipment. The visible equipment could be adapted to regular class use successfully. Also, it was effective in that it reduced waste of gas, minimized danger potential through use of $CO_2$ canisters and candle-sticks, and also increased knowledge about indicators. The new experimental method and equipment affected the students' interest. It is possible that the students' positive participation was due to their interest in the new apparatus and application of the visual senses. The new system was tested fer its effects on teaching content and helping to produce sustained memory of the content. There were no significant differences between the groups in terms of content learning on initial content memory. However, when students in both groups were tested 4 months later, the visual experiment group sustained memory performance, while the other group showed a significant decrease. Generally, boys score higher than girls in terms of interest and participation in experimental activities. In this case, however, there were no difference between groups. It may have been due to introduction of new equipment and different methods from the textbooks. So, this could increase participation in science using various experiments.