• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2006.11a
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• pp.177-180
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• 2006

This study is to make a basic study if solid zinc (Zn) can be used for buried reference electrode, so we examined the adequacy of zinc as reference electrode by using zinc which showed regular electrode for buried period. The deference of electric potential if zinc electrode for corrosion factor such as soil resistivity or pH didn't show fixed trend and there was no clear trend on the change of measurement period. From field test, it is known that the natural electric potential difference of CSE electrode and zinc electrode is 1,100mV, but the electric potential of zinc electrode for CSE electrode in the natural soil and copying soil was 1,094~1,158mV. There was no fixed trend on the change of measurement period and electric potential difference of zinc electrode for corrosion factors such as soil resistivity or pH. Consequently, there was 40~60mV of electric potential difference in every copying soil during the experiment measurement.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.03a
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• pp.65-72
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• 2001

Since Pyoungtaek thermal power plant began using natural gas in 1986, the annual using volume has rapidly increased and reached 12.7 million tons in 1999. When the natural gas is cooled to a temperature of approximately -162$^{\circ}$C at atmospheric pressure, it condenses to a liquid called liquefied natural gas(LNG). LNG has a special characters such as odorless, colorless, non-corrosive, and non-toxic. So, LNG storage tank, tanker ship, transfer pipelines are required the special storage and transportation systems and technology. The presently operating LNG terminals are Pyongtaek and Inchon terminals. A total of 19 above-ground LNG storage tanks(100 thousand ㎘ grade) are currently in operation with a sendout capacity of 4,360tons/hour. To meet the growing domestic demand of LNG supply, the Inchon receiving terminal is expanding(six in-ground tank) and constructing a third LNG terminal at Tongyong. In this paper, case study on seepage analysis and countermeasure against increasing the seepage volume of in-ground LNG storage tank excavation work is reported. The results of an additional seepage analysis are presented to verify the design seepage volume of assumption section and seepage volume after curtain-grouting in the slurry wall.

• Journal of the Korean Geotechnical Society
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• v.20 no.7
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• pp.33-44
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• 2004

This paper is focused on the spatial variability of measured strong motion data during earthquake and its relationship with the performance of water distribution pipelines and residential buildings. Analyses of strong motion and the correlations of peak ground velocity (PGV) and pipeline and building damage were conducted with a very large geographical information system (GIS) database including the relationship of time and earthquake intensity and the measured location, and Kriging spatial statistics. Kriging was used to develop regressions of pipeline repair rate (RR) and residential building damage ratio (DR) associated with $90\%$ confidence peak ground velocity (PGV). Such regressions using Kriging provide an explicit means of characterizing the uncertainty embodied in the strong motion data compared with other spacial statistics such as inverse distance method.

• Journal of the Korean Institute of Gas
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• v.5 no.3 s.15
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• pp.29-35
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• 2001

Direct current corrosion have being investigated by lots of scientists but alternating current corrosion was ignored because the corrosion rate by AC was very small. Recently however, AC corrosion accidents have been reported in many other countries. So the study of AC corrosion is to be necessary In these days. In this paper, several experiments which intentionally imposed the AC or DC to the specimens also imposed AC and DC at the same time was carried out in the laboratory to examine the AC corrosion characteristics and in addition applied the same way in the field. Moreover, while the field investigations of the abnormal corrosion failures, It was the AC that caused one of corrosion failures.

• Journal of the Korean Institute of Gas
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• v.15 no.1
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• pp.74-80
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• 2011

Recently, needs for extending remaining life and integrity of the aged energy plants are increased since the most domestic plants have been operated over 10 years. This need makes RAM (reliability, availability and maintainability) of the plant become more significant. RBI (risk based inspection) is main technology to increase RAM in energy plants. So far RBI has been developed mainly in the field of process plants (chemical/refinery), underground buried pipelines or nuclear power plants. However, the existing RBI procedure is limited mainly to process plants, it need to be extended to the other energy plants such as fossil power plants. In this study, a general RBI procedure for optimized PM (preventive maintenance) is proposed for various energy plants.

• Journal of the Korean Institute of Gas
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• v.17 no.2
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• pp.44-49
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• 2013

Due to rapid rise of consuming rate for natural gas, installation and operation of high pressure natural gas pipeline is inevitable for high rate of gas transportation. Accordingly incidents on the underground high pressure natural gas pipeline come from various reasons will lead to massive release of natural gas and gas dispersion in the air. Further, fire and explosion from ignition of released gas may cause large damage. This study is for release rate, dispersion and flash fire of natural gas to establish a safety management system, setting emergency plan and safety distance.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.466-467
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• 2008

In case of a line-to-ground fault at transmission lines, a portion of fault current will flow into the earth through the footings of the faulted tower causing electrical potential rise nearby the faulted tower footings. In this situation, any buried pipelines or structures nearby the faulted tower can be exposed to the electrical stress by earth potential rise. Although many research works has been conducted on this phenomena, there has been no clear answer of the required separation distance between tower footings and neary buried pipeline because of its dependancy on the soil electrical charactersics of the concerned area and the faulted system.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.868-869
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• 2015

지하 매설된 가스배관을 정기적으로 검사하기 위해서 가스 공급 및 용역업체에서는 주로 비피과검사 탐상장비인 MFL(Magnetic Flux Leakage) PIG(Pipeline Inspection Gauge)를 사용한다. 기존의 MFL PIG는 배관 내 유체(가스,오일 등)의 전후차단 압력의 흐름을 이용해 별도의 구동장치 없이 피그를 진행시켜 배관의 결함 유무를 평가하는 시스템이다. 하지만 10기압 이하의 낮은 운영압력과 T 분기관과 같이 급격한 곡관부가 존재하는 직경 16인치 이하의 도시가스 배관에는 기존의 시스템을 적용하기 어렵다. 이처럼 기존 MFL PIG의 적용이 불가한 도시가스 배관(직경 16인치 이하)을 활주하기 위해서는 우선 비파괴검사 시스템을 견인할 수 있는 추진 로봇이 필요하고 추진로봇에 적합한 자기누설 비파괴검사 시스템의 개발이 필요하다. 또한 비파괴검사 장비의 센서 시스템은 결함신호를 탐지하여 결함의 발생유무 및 결함의 형상을 판별하는 성능도 중요하다. 본 논문에서는 16인치 도시가스 배관의 검사를 위한 자기누설 비파괴검사 시스템의 기초설계와 대상 시스템의 자기적 특성을 분석한다. 또한 배관 외벽의 결함 발생 유무에 따른 자기누설 신호의 크기 및 분포변화를 3차원 유한요소법을 이용해 해석하여, 결함 검출 신호의 특성을 분석하는데 초점을 둔다.

• 대한공업교육학회지
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• v.34 no.1
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• pp.274-286
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• 2009

Fiber optic sensor is widely used in measuring acoustic and vibration. Especially interferometric sensors are more suitable to measure the acoustic signal. In this paper, a Fabry-Perot interferometric fiber optic sensor was used to measure flow induced vibration. This vibration also measured using an accelerometer, and the data was compared to one other. The venture, nozzle, drop barrel, and rapid expansion in the pipeline are the measuring objects. The flow rate is changed from 50 L/min to 150 L/min and the average flow velocity was about 7 m/s. Based on the experimental results the suggested fiber optic sensor detects flow induced vibration effectively. Therefore, this kind of fiber optic sensor can be applied to the monitoring the flow induced noise and vibration such as pipelines, cables, buildings.

• Genomics & Informatics
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• v.15 no.1
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• pp.51-53
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• 2017

High-throughput transcriptome sequencing, also known as RNA sequencing (RNA-Seq), is a standard technology for measuring gene expression with unprecedented accuracy. Numerous bioconductor packages have been developed for the statistical analysis of RNA-Seq data. However, these tools focus on specific aspects of the data analysis pipeline, and are difficult to appropriately integrate with one another due to their disparate data structures and processing methods. They also lack visualization methods to confirm the integrity of the data and the process. In this paper, we propose an R-based RNA-Seq analysis pipeline called TRAPR, an integrated tool that facilitates the statistical analysis and visualization of RNA-Seq expression data. TRAPR provides various functions for data management, the filtering of low-quality data, normalization, transformation, statistical analysis, data visualization, and result visualization that allow researchers to build customized analysis pipelines.