• Journal of the Korea institute for structural maintenance and inspection
• /
• v.24 no.6
• /
• pp.161-170
• /
• 2020

In this study, develop the seismic acceleration measurement data conversion and signal processing algorithms for improve the operational efficiency of the seismic acceleration measurement system installed for public facilities. Through the analysis of the seismic acceleration time history data, the evaluation methods and criteria and evaluating the safety of buildings were proposed. The system was applied to the test bed building to verify its operation and usability. It is expected to be used as a decision making support data and determining the direction and priority of disaster response in the event of an earthquake.

• Journal of the Korean Institute of Gas
• /
• v.18 no.6
• /
• pp.32-39
• /
• 2014

To ensure the reliability of the safety system so that handing large quantities of hazardous materials in chemical plant is considered basic information in chemical process design. However, the reliability of the production system may be reduced when the reliability of the safety system emphasized in order to ensure the safety of chemical process. It is necessary to balance the reliability of the production system and reliability of the safety. In this study, a quantitative risk assessment was performed by selecting the furnace process, which is widely used in the chemical plant in order to suggest a way to ensure the safety and productivity of chemical process, based on the quantitative data. Quantitative risk assessment methodology have been used directed graph analysis methodology. It is possible to evaluate the reliability of the safety system and the production system. In this study, the optimum system design requirement to improve the safety and the productivity of the furnace is two-out-of-three logic for TT and PT.

• Journal of the Korean Institute of Gas
• /
• v.27 no.3
• /
• pp.35-40
• /
• 2023

In order to prevent an ammonia container from bursting under conditions such as overcharging and abnormal temperature rise, it is necessary to prepare accident prevention measures through analysis of the operating mechanism of the Thermally Activated Pressure Relief Devices (TPRD) attached to the container. In this study, stress analysis acting on the ammonia container under pressurized conditions, density change analysis according to temperature change, and correlation between container filling amount and temperature and pressure change were presented. In addition, the maximum filling amount of the ammonia container was calculated, and the temperature and pressure at the filling amount were calculated through the phase equilibrium diagram. Based on this, the appropriate melting point of the Thermally Activated Pressure Relief Devices was derived and verified through a melting temperature experiment. Based on the results of this study, conditions for preventing ammonia container rupture accidents were suggested.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.2
• /
• pp.414-421
• /
• 2022

Subsea oil and gas exploration is increasingly moving into deeper water depths, and typically, subsea pipelines operate under high pressure and temperature conditions. Owing to the difference in these components, the axial force in the pipe is accumulated. When a pipeline is operated at a high internal pressure and temperature, it will attempt to expand and contract for differential temperature changes. Typically, the line is not free to move because of the plane strain constraints in the longitudinal direction and soil friction effects. For a positive differential temperature, it will be subjected to an axial compressive load, and when this load reaches a certain critical value, the pipe may experience vertical (upheaval buckling) or lateral (snaking buckling) movements that can jeopardize the structural integrity of the pipeline. In these circumstances, the pipeline behavior should be evaluated to ensure the pipeline structural integrity during operation in those demanding loading conditions. Performing this analysis, the correct mitigation measures for thermal buckling can be considered either by accepting bar buckling but preventing the development of excessive bending moment or by preventing any occurrence of bending.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.26 no.1
• /
• pp.1-7
• /
• 2013

Structural design and analysis of a coiling arm unloading machine for submarine cable have been originally conducted in this study. Three-dimensional CAD modeling process is practically applied for the structural design in detail. Finite element method(FEM) and multi-body dynamics(MBD) analyses are also used to verify the safety and required motions of the designed coiling arm structure. The effective moving functions of the designed coiling arm with respect to rotational and radial motions are achieved by adopting bearing-roller mechanical parts and hydraulic system. Critical design loading conditions due to its self weight, carrying cables, offshore wind, and hydraulic system over operation conditions are considered for the present structural analyses. In addition, possible inclined ground conditions for the installation of the designed coiling arm are also considered to verify overturn stability. The present hydraulic type coiling arm system is originally designed and developed in this study. The developed coiling arm has been installed at a harbor, successfully tested its operational functions, and finished practical unloading mission of the submarine cable.

• The Journal of the Acoustical Society of Korea
• /
• v.43 no.1
• /
• pp.39-48
• /
• 2024

A car horn serves a crucial safety role as a means of communication between drivers and a part that alerts pedestrians in advance. While previous studies have utilized finite element method and electric circuit model to simulate and analyze characteristics of the car horns, there remains a lack of research on design methods of a trumpet horn. This paper presents a design approach that predicts the operating frequency based on the acoustic reactance at the throat of the horn, once the vibrating part is determined. We deal with a horn combining both an exponential horn and a waveguide in the acoustic section, and confirm that the acoustic reactance at the horn throat measured by impedance tube experiment agrees well compared with the numerical result obtained using the finite element method. The resonance frequency of the car horn is predicted using the COMSOL Multiphysics finite element numerical analysis model, and the proposed design method is validated by measuring the operating frequency of the designed horn in a sound pressure experiment. As a result, the resonance measured in a semi-anechoic chamber environment by applying a DC voltage of 12 [V] excluding the holder occurs accurately within a few [Hz] of the design operating frequency. This paper discuss the design method of a trumpet horn from the perspective of the horn's acoustic reactance, and is expected to be useful for designing horn systems.

• Proceedings of the KIEE Conference
• /
• 2002.07b
• /
• pp.1280-1282
• /
• 2002

도시철도유지보수 정보화시스템 구축의 일환으로 3차원 형상정보화를 구축하여 사용자의 편리와 유지보수시 안전성을 향상하고자 시스템을 개발한다. 본 연구에서는 3차원 형상정보에 대한 자료 검토와 적용가능성을 검토하고 시작품을 개발한다. WEB기술의 발달로 더욱 형상정보에 대한 필요성이 제기되었고 유지보수작업과 작동원리 더 나아가 공학적 요소까지 적용하여 도시철도의 안전과 유지보수 비용을 절감하게 될 것이다.

• Journal of Energy Engineering
• /
• v.23 no.3
• /
• pp.96-101
• /
• 2014

The Instrument Channel setpoints of the Reactor Protection System(RPS) and the Engineered Safety Feature Actuation System(ESFAS) ensures the safety of Nuclear Power Plants (NPPs), and the actuation of the protection system should be guaranteed on power change condition. The goal of this study is to verify the appropriateness of the sensor drift and rack drift which are important factors for setpoints evaluation and to improve the setpoints margin using the operation data, design specifications and operation manuals of the NPPS.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 1994.04a
• /
• pp.3-9
• /
• 1994

초고강도 마레이징강의 초박판 고정밀 연소관의 유동성형공정 조건을 도출하기 위하여 치수제어 시험을 실시하고 가공열처리 공정이 적용된 연소관의 물성 및 구조시험을 통해 신뢰성을 평가하였다. 두께 0.5mm 이하인 초박판 연소관의 유동성형에서 두께증가 현상은 성형속도 0.5-0.75mm/rev에서 X롤러의 성형비를 상대적으로 10%이하로 하고. 성형반경을 4mm로 작게 함으로써 제어할 수 있었으며. 이와 같이 개발된 연소관은 인장강도가 300ksi 이상으로 크게 강화되었고, 예상 최대작동압력에 대한 안전계수가 1.3 이상으로서 구조적 안전성이 입증되었다.

• Journal of the KSME
• /
• v.34 no.10
• /
• pp.764-769
• /
• 1994

본 연구에서 개발한 KARV-2의특징은 저가의 소형시스템이다. 4인승 소형지프차에 모든 컨트 롤시스템을 장착하고도 외부에 별로 표가 나지 않을 정도임에도 그 성능 면에서는 고속도로를 자율주행할 수 있다는 점이다. 첨단기술의 개발과 더불어 이 차량의 성능도 계속 개선될 것이다. 언젠가는 궤도 위를 달리는 기차와 같이 정확하고 안전하게 주행할 수 있어, 탑승자는 마음놓고 그저 신문을 읽거나 음료수를 마시면서 스쳐 가는 경관을 즐길 수 있는 시기가 곧 도래할 것 으로 믿는 다. 이를 위하여는 차량작동의 신뢰도 향상이 절대 전제조건이다. 앞으로는 일기조건 이나 주야에 관계없이 마치궤도 위를 달리는 기차처럼 안전하게 주행할 수 있는 시스템의 개발이 필요하다. 또한 고속도로가 아닌 시내주행을 위해서는 노면표식인식, 도로표지판 인식, 신호등 인식 등 해결되어야 할 문제들이 산적해 있는 상황이다.