• Journal of Energy Engineering
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• v.26 no.3
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• pp.123-130
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• 2017

The district heating system has been successfully implemented with higher efficiency levels of energy production and reduction of carbon emissions during heat generation. Traditionally the system consisted of small number of production and demand sites, but, recently it has evolved into a network with large number of sites interconnected each other. By connecting multiple sites into a network, heat from low-cost production sites can be supplied to distant demand sites so as to lower the total operation cost. In this study, we simulate and analyze distict heating networks focused on critical links. a critical link is defined as a link in which capacity is fully utilized. If a newtork has critical links, then those cricial links become bottlenecks and it is difficult to improve the overall network efficiency.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.2
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• pp.347-354
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• 2021

In the equipment industry such as chemical plants, high temperature, high pressure, and toxic fluids move between various facilities through piping. The movement and damage of pipes due to changes in the surrounding environment such as temperature changes, vibrations, earthquakes, and ground subsidence often lead to major accidents involving personal injury. In order to prevent such an accident, various types of expansion joints are used to absorb and supplement various shocks applied to the pipe to prevent accidents in advance. Therefore, it is very important to measure the deformation of the used expansion joint and predict its lifespan to prevent a major accident. In this paper, the deformation of the expansion joint was understood as a kind of motion, and the change was measured using a Hall Effect Sensor and a 9-Axis Sensor. In addition, we studied a system that can predict the deformation of expansion joints by collecting and analyzing the measured data using a general-purpose microcomputer (Arduino Board) and C language.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.257-265
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• 2016

The purpose of this study was to develop a strainer that could protect a flow system by blocking the introduction of foreign substances into the pipe of industrial or architectural facilities. Strainers are installed at the front tip of valves, machines, or pumps in the piping line of clean water, oil, or gas. There are Y-type, U-type, and T-type strainers. The study identified problems with the Y-type strainers, develop a "C-type strainer with its inlet and outlet on a straight line" as a more improved new model, and compared them in functions in a full-scale strainer test. The study conducted a full-scale strainer test according to four situations at the flow laboratory of Korea Research Institute of Standards and Science by using the old Y-type strainer and C-type strainer 50A. The test results show that the C-type strainer had a higher capacity coefficient(Kv) than the Y-type one, recording 74.9% when there was no screen, 54.5% when there were no foreign substances in the screen, 54.2% when there was a 15% accumulation of foreign substances, and 52.4% when there was a 30% accumulation of foreign substances. The investigator conducted a test only with the 50A type due to the limitations of life-size strainers, but the results demonstrate that the C-type strainer had better flow characteristics than the Y-type one.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.4
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• pp.650-656
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• 2018

The TFT-LCD industry is a kind of large-scale industrial Giant Microelectronics device industry and has a similar semiconductor process technology. Wet etching forms a relatively large proportion of the entire TFT process, but the number of published research papers on this topic is limited. The main reason for this is that the components of the etchant, in which the reaction takes place, are confidential and rarely publicized. Aluminum (Al) and copper (Cu), which have been used in recent years for the manufacture of large area LCDs, are very difficult materials to process using wet etching. Cu, a low-resistance material, can only be used in the wet etching process, and is used as a substitute for Al due to its high speed etching, low failure rate, and low power consumption. Further, the abnormal reaction of hydrogen peroxide ($H_2O_2$), which is used as an etching solution, requires additional piping and electrical safety devices. This paper proposes a method of minimizing the damage to the plant in the case of adverse reactions, though it cannot limit the adverse reaction of hydrogen peroxide. In recent years, there have been many cases in which aluminum etching equipment has been changed to copper. This paper presents a countermeasure against abnormal reactions by implementing safety PLC with a high safety grade.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.11a
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• pp.874-877
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• 2007

최근 건설 산업이 고도화, 지능화됨에 따라 건설자재정보의 효율적인 관리방안으로 RFID 기술을 이용하려는 연구 및 적용 사례가 증가 하고 있다. RFID(Radio Frequency Identification)란 라디오 주파수를 이용한 무선인식 기법을 뜻하는 것으로 건설자재에 RFID Transponder(이하 태그)를 부착하여 생산, 유통, 설비 등 전 과정의 정보 추적 및 관리가 가능하다. 그러나 RFID 시스템 특성상 전자기장이 형성되는 철골자재나 수분이 포함된 콘크리트, 도료(안료) 등의 자재에서는 RFID 적용이 쉽지 않다. 또한, 현재 사용 중인 RFID 장비마저도 표준화 되어 있지 않고 사용 주파수 대역 또한 각각 다르기 때문에 건설자재에 적용하기위한 RFID 시스템의 표준화 및 규격화가 절실하다. 본 논문에서는 건설자재에 RFID를 적용하기 위한 표준화 방향을 제시하는 기초 연구로써 목재, 철재 빔, 도료(안료), 콘크리트, 배관자재(철/동/PE)에 Passive Type의 일반(Pager) 태그, 금속 태그, 액체형 태그를 부착 매립하여 125KHz, 13.56MHz, 900MHz의 주파수 대역과 자재 물성별 인식거리 및 인식률 시험을 진행하여 건설자재에 RFID를 적용하기위한 표준 주파수 대역 및 재질에 따른 적정 태그를 제시하고자 한다.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.335-342
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• 2018

Various technologies to cope with the energy and environmental issues related to the chemical and electric power industry are in development and demonstration stage. Especially, the absorption process of carbon dioxide ($CO_2$) using amine solution is a key technology of the $CO_2$ capture and storage (CCS). In this study, we identify the major risk factors and suggest strategies for safety improvement by analyzing and assessing commercial the amine-based $CO_2$ separation process. HAZOP method was used to assess the risk for the process. We provide facilities and operational strategies to mitigate or eliminate major risk factors by assessing the relative ranks of identified risk factors using a risk matrix.

• Journal of the Korean Institute of Gas
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• v.12 no.2
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• pp.48-52
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• 2008

According to extremely industrial growth, gas facilities, equipments and chemical plants are gradually increased due to incremental demands of annual amount of gases. The safety management of gases, however, is still far from their requirements. Methane, the principal ingredient of natural gas, is inflammable and explosive and is much used in factories and houses. Therefore, these gas safety management is essential. So, we, with a program of the gas safety management, hope to develop the detection system of methane gas leak using mid-infrared ray LED and PD with $3.2\;{\mu}m$. The cryogenic cooling device is indispensible at laser but needless at LED driven on the room temperature if manufacturing optical sensor with $3.2\;{\mu}m$. It, consequently, is not only possible to implement for subminiature and portable type but also able to speedily detect methane of extremely small quantities because the $CH_4$ absorption intensity at $3.2\;{\mu}m$ is stronger than that at $1.67\;{\mu}m$. Our objective of research is to prevent gas leak accidents from occurring previously and to minimize the extent of damage from them.

• Journal of the Korean Society for Nondestructive Testing
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• v.29 no.5
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• pp.427-435
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• 2009

Cylindrical structures such as pipes and shafts are widely used in various industrial facilities. Recently, researches on magnetostrictive transduction of torsional waves have been actively reported for the nondestructive evaluation of those cylindrical structures. However, the existing magnetostrictive patch transducer has somewhat inconvenient and time.consuming process like patch bonding to a structure since it should employ a magnetostrictive patch having strong magnetostriction. To overcome these limitations of the existing transducer, in this work, we develop a novel modular magnetostrictive transducer to generate and measure torsional waves to inspect a cylindrical structure. The proposed transducer can be applied as viscous liquid coupling with shear couplant or dry coupling without coupling media instead of patch bonding to a structure. We describe a detailed structure of the modular transducer and conduct some experiments to verify its performance.