• Title/Summary/Keyword: 안전설비

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A Study on Smart Ground Resistance Measurement Technology Based on Aduino (아두이노 기반 IT융합 스마트 대지저항 측정 기술 연구)

  • Kim, Hong Yong
    • Journal of the Society of Disaster Information
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    • v.17 no.4
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    • pp.684-693
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    • 2021
  • Purpose: The purpose is to establish a safe facility environment from abnormal voltages such as lightning by developing a smart land resistance measuring device that can acquire real-time land resistance data using Arduino. Method: This paper studied design models and application cases by developing a land resistance acquisition and analysis system with Arduino and a power line communication (PLC) system. Some sites in the wind power generation complex in Gyeongsangnam-do were selected as test beds, and real-time land resistance data applied with new technologies were obtained. The electrode arrangement adopted a smart electrode arrangement using a combination of a Wenner four electrode arrangement and a Schlumberger electrode arrangement. Result: First, the characteristic of this technology is that the depth of smart multi-electrodes is organized differently to reduce the error range of the acquired data even in the stratigraphic structure with specificity between floors. Second, IT convergence technology was applied to enable real-time transmission and reception of information on land resistance data acquired from smart ground electrodes through the Internet of Things. Finally, it is possible to establish a regular management system and analyze big data accumulated in the server to check the trend of changes in various elements, and to model the optimal ground algorithm and ground system design for the IT convergence environment. Conclusion: This technology will reduce surge damage caused by lightning on urban infrastructure underlying the 4th industrial era and design an optimized ground system model to protect the safety and life of users. It is also expected to secure intellectual property rights of pure domestic technology to create jobs and revitalize our industry, which has been stagnant as a pandemic in the post-COVID-19 era.

Risk Assessment of Semiconductor PR Process based on Frequency Analysis of Flammable Material Leakage (반도체 PR 공정의 인화성 물질 누출 빈도분석을 통한 위험성 평가)

  • Park, Myeongnam;Chun, Kwang-Su;Yi, Jinseok;Shin, Dongil
    • Journal of the Korean Institute of Gas
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    • v.25 no.5
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    • pp.1-10
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    • 2021
  • Semiconductor Photo Resist (PR) automation equipment uses a mixture of several flammable substances, and when it leaks during the process, it can lead to various accidents, therefore, risk assessment is necessary. This study analyzed the frequency of leakage of Acetone and PGMEA used in PR automation equipment and the frequency at which such leakage could lead to a fire accident through the frequency analysis method, and evaluated the need for additional risk reduction measures in the current facility. Based on the process leak data and ignition probability data of IOGP, leak frequency analysis and ignition probability were derived, and the frequency of actual fire accidents was analyzed by combining them. The frequency of material leakage in semiconductor PR process is 7.30E-03/year, and fire accidents can occur by acetone that exists above the flash point when the material is leaked, the frequency was calculated at the level of 1.24E-05/year. According to the UK HSE, for a major accident occurring with a frequency of 1.24E-05/year, it is defined as "Broadly Acceptable", a level that does not require additional measures for risk reduction when it causes 7 or less deaths, and due to the process operated by two people, no additional risk reduction are required.

Evaluation of Smoke Control Performance of Ventilation System Using by Hot Smoke Test (Hot Smoke Test를 이용한 주차장 환기설비의 제연 성능평가)

  • Joung, Suckhwan
    • Journal of Korean Society of Disaster and Security
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    • v.12 no.2
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    • pp.47-56
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    • 2019
  • Recently, in order to overcome the difficulty of entering a fire source due to the occurrence of a large amount of smoke in the event of a fire in a parking lot, it has used that a method of discharge smoke using air supply, exhaust fans and jet fans installed for ventilation of parking lots. In this study, the variation of flow in the smoke layer was observed using CCTV under two conditions, in which only the air supply fan operates and the manned fan operates together, and the temperature around the plume was compared to Albert eq. to assess its suitability as a parking lot ventilation performance evaluation method. As a result, it was found that the smoke layer could be disturbed if the Jet Fan was operated at the same time, which could lead to the possibility of an initial evacuation disturbance. However, the additional operation of the Jet Fan has been confirmed by the observation CCTV that the emission performance is improved, which is believed to help conduct the suppression operation. The temperature around the plume was measured and compared to Alpert eq, and was analyzed to be about $2^{\circ}C$ lower at the center axis of the plume and $9.0^{\circ}C$ higher at 8 m in the direction of the discharge of smoke. The results of temperature measurements around the plume were lower than the maximum temperature expected in AS 4391 and did not exceed the expected temperature risk caused by the experiment. As with these results, the temperature risk from the progression of hot smoke tests is foreseeable, so it will be available as one of the general evaluation methods for assessing smoke control performance in a parking lot without relevant criteria.

A Study of Economic Efficiency and Environmental Performance Due to the Conversion of the 7th and 8th Basic Plan for Long-term Power Supply and Demand (제7차 및 제8차 전력수급기본계획 전원 구성 전환에 따른 경제성 및 환경성 변화 분석 연구)

  • Cho, Sungjin;Yoon, Teayeon;Kim, Yoon Kyung
    • Environmental and Resource Economics Review
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    • v.28 no.2
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    • pp.201-229
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    • 2019
  • This paper estimates the effects of generation mix changes in the $7^{th}$ and $8^{th}$ Basic Plan for Long-term Power Supply and Demand from two aspects: economic efficiency through electricity prices and environmental performance through $CO_2$ and air pollutants(NOx, SOx, PM) emissions. Particularly, we examined additional generation mix conversion paths that take into account the trade-off between economic efficiency and environmental performance through scenario analysis. According to our results, the conversion from the $7^{th}$ plan to the $8^{th}$ plan should increase the electricity prices in the mid- and long-term, while reducing GHG and air pollutants emissions at the same time. The alternative generation mix that combines $7^{th}$ and $8^{th}$ plans shows that there exists a path to mitigate the trade-off between economic and environmental in the long-term. It will be next to impossible to derive a optimal generation mix that simultaneously considers the core values, such as supply stability, environmental performance, economic efficiency, energy safety and energy security, when establishing the power supply and demand plan. However, by exploring the effects of various generation mix paths and suggesting near-optimal paths, people can best choose their direction after weighhing all the paths when deciding on a forward-looking generation mix in the long term.

Numerical Analysis on Development of Nozzle Shape for NOVEC Gas Extinguishing System (NOVEC가스 소화설비용 노즐 형상 설계에 대한 수치해석)

  • Yun, Jeong In;Jung, Kyung Kuk;Kim, Ji Sung;Kim, Sung Yoon;Rho, Beom-Seok;Choi, Jae-Hyuk
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.24 no.7
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    • pp.939-944
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    • 2018
  • Clean fire extinguishing agents refer to chemical that can replace Halon 1211 and Halon 1310 according to the Montreal Protocol fermented to protect the Earth's ozone layer. In Korea and abroad, system standardization and performance evaluation of clean fire extinguishing agents are being carried out. This paper proposes an optimal nozzle shape by modeling and numerical analysis of various nozzle shapes based on general clean fire extinguishing system. The ejection speed of the nozzle can be improved by studying three - dimensional modeling of the nozzle for two shapes, Type A and B. Flow analysis was performed on the two types of nozzles and the gas velocity and pressure distribution were measured with different nozzle diameters. It was confirmed that the jetting speed was changed at the nozzle outlet according to the number and diameter of the nozzle holes. The flow rate increased with increasing the pressure regardless of the nozzle hole diameter. Based on the results obtained from the experiment, the K-factor value was deduced. Finally, a nozzle with a 12-hole structure with a 5-mm nozzle hole was proposed.

Numerical Study on the Effect of a Groove of D-type on Internal Flow and Pressure Drop in a Corrugated Pipe (주름관 내부 유동과 압력강하에 대한 D형 그루브의 영향에 관한 수치해석)

  • Hong, Ki Bea;Kim, Dong Woo;Ryou, Hong Sun
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.1
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    • pp.1-8
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    • 2021
  • A corrugated pipe is widely used in firefighting equipment and sprinkler pipes because of its elasticity, which is less damaged by deformation and convenient facilities. However, the corrugated shape of the wall results in complex internal turbulent flow, and it is difficult to predict the pressure drop, which is an important design factor for pipe flow. The pressure drop in the corrugated tube is a function of the shape factors of the pipe wall, such as groove height, length, and pitch. Existing studies have only shown a study of pressure drop due to length changes in the case of D-shaped tubes with less than 5 pitch (P) and height (K) of the rectangular grooves in the tube. In this work, we conduct a numerical study of pressure drop for P/Ks with length and height changes of 2.8, 3.5 and 4.67 with Re Numbers of 55,000, 70,000 and 85,000. The pressure drop in the corrugated tube was interpreted to decrease with smaller P/K. We show that the pressure drop is affected by the change in the groove aspect ratio, and the increase in the height of the groove increases the recirculation area, and the larger the Reynolds number, the greater the pressure drop.

Fabrication and Constructability of a General-Purpose Manufactured Precast Concrete Double Wall (범용 생산설비를 활용한 PC 더블월 제작 및 시공성에 관한 연구)

  • Park, Soon-Jeon
    • Journal of the Korea Institute of Building Construction
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    • v.23 no.4
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    • pp.465-476
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    • 2023
  • This study introduces the development of a precast concrete double-wall, applicable to basement construction in apartment buildings. Unlike traditional precast concrete double walls, the developed double-wall doesn't require specialized manufacturing equipment such as a lathe. The constructability of these advanced technologies was validated through a full-scale mock-up test using the precast concrete double wall. The test specimens were constructed to represent a structural wall with a thickness of 250mm. It was observed that the quality of the in-situ concrete, filled between two single panels of 110mm thickness each, was excellent. The construction efficiency of the developed double-wall system for basement construction in an apartment building was also examined. Expert interviews about installation times of precast concrete elements were conducted to evaluate the speed of the basement floor's installation. The results showed that installation of precast concrete elements, including the proposed double walls, could be completed within 20 to 29 days for a basement in an apartment building. This indicates a three-fold increase in construction efficiency compared to traditional methods relying on in-situ casting.

3D Simulation Study to Develop Automated System for Robotic Application in Food Sorting and Packaging Processes (식품계량 및 포장 공정 로봇 적용 자동화 시스템 개발을 위한 3D 시뮬레이션 연구)

  • Seunghoon Baek;Seung Eel Oh;Ki Hyun Kwon;Tae Hyoung Kim
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.5
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    • pp.230-238
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    • 2023
  • Small and medium-sized food manufacturing enterprises are largely reliant on manual labor, from inputting raw materials to palletizing the final product. Recently, there has been a trend toward smartness and digitization through the implementation of robotics and sensor data technology. In this study, we examined the effectiveness of improvement through 3D simulation on two repetitive work processes within a food manufacturing company. These processes involve workers whose speed cannot match the capacity of the applied equipment. Two manual processes were selected: the weighing and packing process performed by workers after skewer assembly, and the manual batch process of counting randomly delivered frozen foods, packing (both internal and external), and palletizing. The production volume, utilization rate, and number of workers were chosen as verification indicators. As a result of the simulation for improving the 3D process, production increased by 13.5% and 56.8% compared to the existing process, respectively. This was particularly evident in the process of applying palletizing robots. In both processes, as the utilization rate and number of input workers decreased, robots could replace tasks with high worker fatigue, thereby reducing work overload. This study demonstrates the potential to visually compare the process flow improvement using 3D simulations and confirms the possibility of pre-validation for improvement.

Investigating Key Security Factors in Smart Factory: Focusing on Priority Analysis Using AHP Method (스마트팩토리의 주요 보안요인 연구: AHP를 활용한 우선순위 분석을 중심으로)

  • Jin Hoh;Ae Ri Lee
    • Information Systems Review
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    • v.22 no.4
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    • pp.185-203
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    • 2020
  • With the advent of 4th industrial revolution, the manufacturing industry is converging with ICT and changing into the era of smart manufacturing. In the smart factory, all machines and facilities are connected based on ICT, and thus security should be further strengthened as it is exposed to complex security threats that were not previously recognized. To reduce the risk of security incidents and successfully implement smart factories, it is necessary to identify key security factors to be applied, taking into account the characteristics of the industrial environment of smart factories utilizing ICT. In this study, we propose a 'hierarchical classification model of security factors in smart factory' that includes terminal, network, platform/service categories and analyze the importance of security factors to be applied when developing smart factories. We conducted an assessment of importance of security factors to the groups of smart factories and security experts. In this study, the relative importance of security factors of smart factory was derived by using AHP technique, and the priority among the security factors is presented. Based on the results of this research, it contributes to building the smart factory more securely and establishing information security required in the era of smart manufacturing.

Bayesian Network-based Probabilistic Safety Assessment for Multi-Hazard of Earthquake-Induced Fire and Explosion (베이지안 네트워크를 이용한 지진 유발 화재・폭발 복합재해 확률론적 안전성 평가)

  • Se-Hyeok Lee;Uichan Seok;Junho Song
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.37 no.3
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    • pp.205-216
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    • 2024
  • Recently, seismic Probabilistic Safety Assessment (PSA) methods have been developed for process plants, such as gas plants, oil refineries, and chemical plants. The framework originated from the PSA of nuclear power plants, which aims to assess the risk of reactor core damage. The original PSA method was modified to adopt the characteristics of a process plant whose purpose is continuous operation without shutdown. Therefore, a fault tree, whose top event is shut down, was constructed and transformed into a Bayesian Network (BN), a probabilistic graph model, for efficient risk-informed decision-making. In this research, the fault tree-based BN from the previous research is further developed to consider the multi-hazard of earthquake-induced fire and explosion (EQ-induced F&E). For this purpose, an event tree describing the occurrence of fire and explosion from a release is first constructed and transformed into a BN. And then, this BN is connected to the previous BN model developed for seismic PSA. A virtual plot plan of a gas plant is introduced as a basis for the construction of the specific EQ-induced F&E BN to test the proposed BN framework. The paper demonstrates the method through two examples of risk-informed decision-making. In particular, the second example verifies how the proposed method can establish a repair and retrofit strategy when a shutdown occurs in a process plant.