• Title/Summary/Keyword: protection technique.

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Cathodic Protection of Onshore Buried Pipelines Considering Economic Feasibility and Maintenance

  • Choi, Byoung-Yeol;Lee, Sang-Gil;Kim, Jin-Kwang;Oh, Jin-Soo
    • Journal of Advanced Research in Ocean Engineering
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    • v.2 no.4
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    • pp.158-168
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    • 2016
  • During the installation of crude oil or gas pipelines, which pass through onshore buried pipelines or onshore pipeline from subsea pipeline to onshore plant, countermeasures need to be implemented so as to ensure a sufficient design life by protecting the steel pipes against corrosion. This can be achieved through impressed current cathodic protection method for onshore pipelines and through galvanic sacrificial anode corrosion protection method for offshore pipelines. In particular, in the case of impressed current cathodic protection, isolation joint flanges should be used. However, this makes maintenance control difficult with its installation having a negative impact on price. Therefore, in this study, the most suitable methodology for onshore pipeline protection between galvanic sacrificial anode corrosion protection and impressed current cathodic protection method will be introduced. In oil and gas transportation facilities, the media can be carried to the end users via onshore buried and/or offshore pipeline. It is imperative for the field operators, pipeline engineers, and designers to be corrosion conscious as the pipelines would undergo material degradations due to corrosion. The mitigation can be achieved with the introduction of an impressed current cathodic protection method for onshore buried pipelines and a galvanic sacrificial anode corrosion protection method for offshore pipelines. In the case of impressed current cathodic protection, isolation joint flanges should be used to discontinuity. However, this makes maintenance control to be difficult when its installation has a negative impact on the price. In this study, the most suitable corrosion protection technique between galvanic sacrificial anode corrosion protection and impressed current cathodic protection is introduced for (economic life of) onshore buried pipeline.

Data hiding technique using image pixel value and spatial encryption technique

  • Jung, Soo-Mok
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.3
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    • pp.50-55
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    • 2021
  • In this paper, we proposed a technique for hiding the double-encrypted confidential data in the image using the pixel value of the image and the spatial encryption technique. The proposed technique inserts encrypted confidential data into the LSB of an image pixel in order to maintain high image quality. The stego-image generated by hiding the encrypted confidential data has very good quality and is visually indistinguishable from the original cover image, so that it is impossible to recognize whether the confidential data is hidden in the stego-image. It is possible to extract the original confidential data from the stego-image without loss. By conducting an experiment on the proposed technique, it was confirmed that the proposed technique is an effective technique for the practical application of data hiding. The proposed technique can be used in applications such as military and intellectual property protection that require high security.

A Combined Procedure of Direct Question Method and Modified Randomized Response Technique for Estimating Population Proportion

  • Kim, Hyuk-Joo
    • Journal of the Korean Data and Information Science Society
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    • v.14 no.4
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    • pp.877-887
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    • 2003
  • A two-stage procedure is proposed to estimate the population proportion of a sensitive group. The proposed procedure is obtained by combining the direct question method and a modified randomized response technique. It is verified that the proposed procedure is more efficient than existing methods under some mild conditions.

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Fault Types-Classification Technique in Radial Distribution System Using Wavelet Transform (Wavelet 변환을 이용한 방사상식 배전계통에서의 고장판별에 관한 연구)

  • Kim, Kyoung-Ho;Kim, Nam-Yoel;Lee, Jong-Beom
    • Proceedings of the KIEE Conference
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    • 2001.07a
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    • pp.488-490
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    • 2001
  • It is important to catch or classify fault types by any detecting technique for distribution protection. This paper proposes the technique to classify the fault types using wavelet transform in radial distribution line. Modeling of the radial distribution line is simulated using PSCAD/EMTDC and wavelet transform is performed in the Matlab program.

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A Study of Real Scale Experiment on Protection Technique of Levee Overflow Failure Using Mixed Bio-Polymer and Riprap (피마자유기반 바이오폴리머와 골재를 혼합한 제방월류 보강제 실규모 실험연구)

  • Joongu, Kang;Hong-Kyu, Ahn
    • Ecology and Resilient Infrastructure
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    • v.10 no.1
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    • pp.1-10
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    • 2023
  • Developmental technique is mixed bio-polymer and riprap to protect the breaking of a levee. Purpose of new technique is restraint from scour and failure of bankside. Technique of this research can apply shore protection and embankment overflow reinforcement works. Because This technique is easy for construction. In order to apply the technique in fields, It is need to conduct the test-bed or real scale experiment study for stability-guaranteed. In case of embankment overflow reinforcement works, It is difficult to conduct test bed in the field. Real scale experiment was conducted in River Experiment Center. Purpose of real scale experiment is to reappear disaster scene by embankment overflow and verify restraint from scour and failure about the technique. In this experiment results, We can find the strength effect of mixed bio-polymer and riprap.

Comparative Studies of Frequency Estimation Method for Fault Disturbance Recorder (고장 왜란 기록기를 위한 주파수 추정 기법의 비교 연구)

  • Park, Chul-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.61 no.2
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    • pp.87-92
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    • 2012
  • Voltage and current phasor estimation has been executed by GPS-based synchronized PMU, which has become an important way of wide-area blackout protection for the prevention of expending faults in a power system. The PMU technique can not easily get the field data and it is impossible to share information, so that there has been used a FNET(Frequency Monitoring Network) method for the wide-area intelligent protection in USA. It consists of FDR(Fault Disturbance Recorder) and IMS(Information Management System). Therefore, FDR must provide an optimal frequency estimation method that is robust to noise and failure. In this paper, we present comparative studies for the frequency estimation method using IRDWT(Improved Recursive Discrete Wavelet Transform), FRDWT(Fast Recursive Discrete Wavelet Transform), and DFT(Discrete Fourier Transform). The Republic of Korea345[kV] power system modeling data by EMTP-RV are used to evaluate the performance of the proposed two kinds of RDWT(Recursive Discrete Wavelet Transform) and DFT. The simulation results show that the proposed frequency estimation technique using FRDWT could be the optimal frequency measurement method, and thus be applied to FDR.

Electrochemical Characteristics of Zn-mesh Cathodic Protection Systems in Concrete in Natural Seawater at Elevated Temperature

  • Kim, Ki-Joon;Jung, Jin-A;Lee, Woo-Cheol;Jang, Tae-Seub
    • Corrosion Science and Technology
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    • v.6 no.6
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    • pp.269-274
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    • 2007
  • The corrosion of steel in concrete is significant in marine environment. Salt damage is one of the most detrimental causes to concrete bridges and port structures. Especially, the splash and tidal zones around water line are comparatively important in terms of safety and life-time point of view. During the last several decades, cathodic protection (cp) has been commonly accepted as an effective technique for corrosion control in concrete structures. Zn-mesh sacrificial anode has been recently developed and started to apply to the bridge column cp in marine condition. The detailed parameters regarding Zn-mesh cp technique, however, have not well understood so far. This study is to investigate how much Zn-mesh cp influences along the concrete column at elevated temperature. About 100 cm column specimens with eight of 10 cm segment rebars have been used to measure the variation of cp potential with the distance from Zn-mesh anode at both $10^{\circ}C$ and $40^{\circ}C$ in natural seawater. The cp potential change and current diminishment along the column specimens have been discussed for the optimum design of cp by Zn-mesh sacrificial anode.

Preparation of UV protective cotton fabrics by novel UV-curing technique - Using a photocrosslinkable polymer, poly(ethylene glycol) dimethacylate -

  • Kim, Sin-Hee
    • Journal of Fashion Business
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    • v.11 no.6
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    • pp.52-61
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    • 2007
  • To increase the ultraviolet radiation (UVR) protection of cotton fabric, ultraviolet protection (UVP) materials were treated onto cotton fabric using a new technique, UV-curing. A photocrosslinkablepolymer, poly(ethylene glycol) dimethacrylate was used as a UV-curable resin in the presence of a small amount of photoinitiator. Two kinds of UVP materials were used, UV-absorber, 2,2'-dihydroxy-4-methoxy benzophenone, and UV-scatterer, $TiO_2/ZnO$ Pad-dry-cure method in employing these materials onto cotton was also conducted to compare the effectiveness and the washfastness of UVP treatment between curing methods. UVP treated cotton fabric showed a moderate increase in UVP in case of 2,2'-dihydroxy-4-methoxy benzophenone treatment and a high increase in case of $TiO_2/ZnO$. UV-curing method increased the washfastness of UVP property of $TiO_2/ZnO$ treated cotton fabrics. However, in case of 2,2'-dihydroxy-4-methoxy benzophenone, similar wash fastnesses of UV-cured and pad-dry-cured cotton were observed. It can be presumed that 2,2'-dihydroxy-4-methoxy benzophenone was not significantly affected by water since its hydrophobicity. In short, UV-curing of UVP materials onto cotton was successfully done, and treated cotton fabrics showed the increased UVP properties and an increased washfastness in some extent.

Multisignature Suitable for Digital Contents Copyright Protect ion on CDN (디지털 콘텐츠 저작권 보호를 위한 CDN에서 다중서명)

  • Shin, Seung-Soo;Kim, Duck-Sool
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.4 s.36
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    • pp.77-85
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    • 2005
  • Digital copyright protection is important in the protective side of effort to have leaned to in property right and it which are intelligent of an author and is very important for development of digital contents industry. It is the misgovernment that a reproduction is easy as for the digital contents. and the original and a copy have the same characteristic, and it is so, and is experiencing what is hard for protection of copyright and large quantity illegal copy and illegal distribution prevention. CDN needs a copyright protective plan about the digital contents that digital contents providers were written jointly. The paper used a non-repudiation multi-technique for copyright protection about the digital contents which were written jointly. The Non-repudiation multi-technique proved efficiency about this.

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Watermarking Technique for the Digital Contents Protection (디지털콘덴츠 보호를 위한 워터마킹 기술)

  • Song Hag-hyun;Kim Yoon-ho
    • Journal of Digital Contents Society
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    • v.5 no.1
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    • pp.66-72
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    • 2004
  • Beyond the digital world from the analog age, the contents are very easily copied under the illegal conditions and these are rapidly distributed by the information super highway. The increase of ilegal usage and conflict in digital content market would diminish motivation of creators for their work, furthermore break down digital content market on cyberspace. Watermarking technology support to the legal users by the protection technique based chi the digital content copyright protection method(DRM). Most of previous digital watermarking have embeded to the content. In this paper, we have researched the standardization of digital rights management and developed more efficient watermark embedding method.

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