• Title/Summary/Keyword: Science and engineering

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Applicability Estimation of Ballast Non-exchange-type Quick-hardening Track Using a Layer Separation Pouring Method (층 분리주입을 이용한 도상자갈 무교환방식 급속경화궤도의 적용성 평가)

  • Lee, Il Wha;Jung, Young Ho;Lee, Min Soo
    • Journal of the Korean Society for Railway
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    • v.18 no.6
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    • pp.543-551
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    • 2015
  • Quick-hardening track (QHT) is a construction method which is used to change from old ballast track to concrete track. Sufficient time for construction is important, as the construction should be done during operational breaks at night. Most of the time is spent on exchanging the ballast layer. If it is possible to apply the ballast non-exchange type of quick-hardening track, it would be more effective to reduce the construction time and costs. In this paper, pouring materials with high permeability are suggested and a construction method involving a layer separation pouring process considering the void condition is introduced in order to develop ballast non-exchange type of QHT. The separate pouring method can secure the required strength because optimized materials are poured into the upper layer and the lower layer for each void ratio condition. To ensure this process, a rheology analysis was conducted on the design of the pouring materials according to aggregate size, the aggregate distribution, the void ratio, the void size, the tortuosity and the permeability. A polymer series was used as the pouring material of the lower layer to secure the void filling capacity and for adhesion to the fine-grained layer. In addition, magnesium-phosphate ceramic (MPC) was used as the pouring material of the upper layer to secure the void-filling capacity and for adhesion of the coarse-grained layer. As a result of a mechanics test of the materials, satisfactory performance corresponding to existing quick-hardening track was noted.

A Study on the 4th Industrial Revolution and Block Chain Electronic Government -In terms of the prevention of cybercrimes and corruption- (제4차 산업혁명과 블록체인 전자정부에 대한 연구 -사이버범죄와 사이버부패방지 측면에서-)

  • Lee, Sang-Yun;Yoon, Hong-Joo;Seo, Won-Chan
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.1
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    • pp.11-18
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    • 2019
  • This paper explores desirable status of block chain electronic government in relation to the prevention of cybercrimes and corruption. After the research, we suggest four measures to establish desirable status of block chain electronic government. Eventually, transparency is ensured thanks to the core concept of block chain technology, sharing, not only allowing all of the participants to share information and but also preventing them from forging or falsifying information. Furthermore, a wide variety of participants can play a role as monitors in the horizontal structure of governance system, which also assures credibility and reliability on electronic government through trust on block chain itself. Electronic government aims at virtue of expanded electronic democracy which strengthens information democracy. Also, establishment of electronic governance, that emphasizes networking and guarantees, is a desirable image of the future of the fourth industrial revolution. Therefore, the establishment of future electronic government according to the four principles drawn from this paper can be the most suitable model.

A Big Data Based Random Motif Frequency Method for Analyzing Human Proteins (인간 단백질 분석을 위한 빅 데이타 기반 RMF 방법)

  • Kim, Eun-Mi;Jeong, Jong-Cheol;Lee, Bae-Ho
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.6
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    • pp.1397-1404
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    • 2018
  • Due to the technical difficulties and high cost for obtaining 3-dimensional structure data, sequence-based approaches in proteins have not been widely acknowledged. A motif can be defined as any segments in protein or gene sequences. With this simplicity, motifs have been actively and widely used in various areas. However, the motif itself has not been studied comprehensively. The value of this study can be categorized in three fields in order to analyze the human proteins using artificial intelligence method: (1) Based on our best knowledge, this research is the first comprehensive motif analysis by analyzing motifs with all human proteins in Protein Data Bank (PDB) associated with the database of Enzyme Commission (EC) number and Structural Classification of Proteins (SCOP). (2) We deeply analyze the motif in three different categories: pattern, statistical, and functional analysis of clusters. (3) At the last and most importantly, we proposed random motif frequency(RMF) matric that can efficiently distinct the characteristics of proteins by identifying interface residues from non-interface residues and clustering protein functions based on big data while varying the size of random motif.

A Study on the Policy Issues of Basic Research Promotion in Korean Academics (대학의 연구자 주도 기초연구에 대한 주요 정책 이슈 고찰)

  • Park, Kwisun;Kim, Haedo;Jang, Kyeongsu
    • Journal of Korea Technology Innovation Society
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    • v.21 no.3
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    • pp.938-968
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    • 2018
  • Korea's basic research has been rapidly expended in both quantative and qualitative aspect since establishment of 'the Korea Science & Engineering Foundation' in 1977, proclaiming of 'the First Year of Basic Research Promotion' and enactment of 'the Basic Sciences Promotion Act' in 1989. Despite the continuous increment of government basic research funding, the problem of low perceptions of university researchers on the funding increment has been constantly raised. Based on an intrinsic review on the core issues are diagnosed based on Korean academics' basic research status analysis and future challenges are proposed based on the precedent diagnoses. The six key issues that need to take the next step in Korean academics' basic research are as follows: (1) basic research investment in universities, (2) appropriate research expenses for supporting individual researcher, (3) basic research funding allocation method, (4) maintaining the sustainable success rate of research projects, (5) systematic and strategic support for excellent researchers, (6) creating research-immersive environment. The five challenges to promote basic research in academics are as follows: (1) increasing in university research expenses, (2) diversification of basic research funding allocation method, (3) establishment of research field-specified support system and predictable principles, (4) stable and sufficient support for outstanding researchers, (5) reducing burden on research administration.

Effect of RTA Temperature on the Structural and Optical Properties of HfO2 Thin Films (급속 열처리 온도가 HfO2 박막의 구조적 및 광학적 특성에 미치는 효과)

  • Chung, Yeun-Gun;Joung, Yang-Hee;Kang, Seong-Jun
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.3
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    • pp.497-504
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    • 2019
  • We fabricated $HfO_2$ thin films using RF magnetron sputtering method, and investigated structural and optical properties of $HfO_2$ thin films with RTA temperatures in $N_2$ ambient. $HfO_2$ thin films exhibited polycrystalline structure regardless of annealing process, FWHM of M (-111) showed reduction trend. The surface roughness showed the smallest of 3.454 nm at a annealing temperature of $600^{\circ}C$ in result of AFM. All $HfO_2$ thin films showed the transmittance of about 80% in visible light range. By fitting the refractive index from the transmittance and reflectance to the Sellmeir dispersion relation, we can predict the refractive index of the $HfO_2$ thin film according to the wavelength. The $HfO_2$ thin film annealed at $600^{\circ}C$ exhibited a high refractive index of 2.0223 (${\lambda}=632nm$) and an excellent packing factor of 0.963.

Numerical Analysis for Improvement of Windshield Defrost Performance of Electric Vehicle (전기자동차 전면유리 제상성능 개선을 위한 전산수치 해석)

  • Kim, Hyun-Il;Kim, Jae-Sung;Kim, Myung-Il;Lee, Jae Yeol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.5
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    • pp.477-484
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    • 2019
  • As the residence time in the vehicle increases, the passenger desires a pleasant and stable riding environment in addition to the high driving performance of the vehicle. The windshield defrosting performance is one of the performance requirements that is essential for driver's safe driving. In order to improve the defrosting performance of the windshield of a vehicle, relevant elements such as the shape of the defrost nozzle should be appropriately designed. In this paper, CFD based numerical analysis is conducted to improve defrost performance of small electric vehicles. The defrost performance analysis was performed by changing the angle of the defrost nozzle and the guide vane that spray hot air to the windshield of the vehicle. Numerical simulation results show that the defrosting performance is best when the defrost nozzle angle is $70^{\circ}$ and the guide vane installation angle is $60^{\circ}$. Based on the analytical results, the defrosting experiment was performed by fabricating the defrost nozzle and the guide vane. As a result of the experiment, it is confirmed that the frost of windshield is removed by 80% within 20 minutes, and it is judged that the defrost performance satisfying the FVMSS 103 specification is secured.

Different Heterogeneous IoT Data Management Techniques for IoT Cloud Environments (IoT 클라우드 환경을 위한 서로 다른 이기종의 IoT 데이터 관리 기법)

  • Cho, Sung-Nam;Jeong, Yoon-Su
    • Journal of Convergence for Information Technology
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    • v.10 no.12
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    • pp.15-21
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    • 2020
  • Although IoT systems are used in a variety of heterogeneous environments as cloud environments develop, all IoT devices are not provided with reliable protocols and services. This paper proposes an IoT data management technique that can extend the IoT cloud environment to an n-layer multi-level structure so that information collected from different heterogeneous IoT devices can be efficiently sorted and processed. The proposed technique aims to classify and process IoT information by transmitting routing information and weight information through wireless data link data collected from heterogeneous IoT devices. The proposed technique not only delivers information classified from IoT devices to the corresponding routing path but also improves the efficiency of IoT data processing by assigning priority according to weight information. The IoT devices used in the proposed technique use each other's reliable protocols, and queries for other IoT devices locally through a local cloud composed of hierarchical structures have features that ensure scalability because they maintain a certain cost.y channels of IoT information in order to make the most of the multiple antenna technology.

GPR Exploration of Non-metallic Water Pipes Linked with Network RTK (네트워크 RTK와 연계한 비금속 상수관의 GPR 탐사)

  • Lee, Keun-Wang;Park, Joon-Kyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.2
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    • pp.296-301
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    • 2021
  • GPR is used for non-destructive investigations, ground investigations, and underground facilities exploration at construction sites. In this study, the applicability to GPR exploration of water pipes linked to Network RTK was presented. Data on the water supply pipes in the study site were acquired using GPR, and the location and depth of buried water pipes could be measured. The accuracy was evaluated from the GNSS observation performance and showed a deviation of -0.16m ~ 0.15m. This satisfied the equipment performance of the public survey work regulation, suggesting that the exploration of water pipes using GPR is possible. Because GPR does not require grounding installation, as in conventional metal pipe detectors, it will increase the efficiency of work for underground facility exploration. Exploration using GPR can acquire the location and depth of metallic and non-metallic underground facilities, so it can be utilized in the construction of a GIS system. If a comparison of the exploration characteristics is carried out, it will be possible to present various uses of underground facility exploration using GPR.

Oil Storage Tank Inspection using 3D Laser Scanner (3D 레이저스캐너를 활용한 유류 저장탱크의 검사)

  • Park, Joon-Kyu;Lee, Keun-Wang
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.12
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    • pp.867-872
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    • 2020
  • Oil storage tanks are a major structure in chemical industrial complexes. Damage to the structure due to natural disasters or poor management can cause additional damage, such as leakage of chemicals, fire, and explosion, so it is essential to understand the deformation. In this study, data on oil storage tanks were acquired using a 3D laser scanner, and various analyzes were performed for storage tank management by comparing them with design data. Modeling of the oil storage tank was performed using the data and design drawings acquired by a 3D laser scanner. An inspection of the oil storage tank was effectively performed by overlapping. In addition, cross-sectional and exploded views of the deformation were produced to generate visible data on the deformation of the facility, and it was suggested that the oil storage tank had a maximum deformation of -7.16mm through quantitative analysis. Data that can be used for additional work was obtained by producing drawings to be precisely inspected for areas with large deformation. In the future, an inspection of oil storage tanks using 3D laser scanners is quantitative and visible data on oil storage tank deformation. This will greatly improve the efficiency of facility management by rebuilding it.

Relative Corrosion Environment Conditions of Steel Box Members Examined by Corrosion Current Measurement (부식전류 평가를 통한 강박스 부재의 상대적 부식환경 평가)

  • Jin, Yong-Hee;Ha, Min-Gyun;Jeong, Young-Soo;Ahn, Jin-Hee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.24 no.6
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    • pp.171-179
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    • 2020
  • In this study, a local corrosion environment monitoring was conducted using steel box specimen fabricated to be the same as actual steel bridge members. The steel box specimen that obtained the same corrosion environment as a steel bridge was classified into the upper plate, bottom plate and web plate. Atmospheric corrosion monitoring sensors(ACM sensors) were installed in each corrosion monitoring member of a steel box specimen to measure the corrosion current and examine time of wetness for each monitoring member. The time of wetness and accumulated corrosion current of each monitoring member were calculated from the measured corrosion current using ACM sensors. The corrosion environment that appeared for each of the steel box members was evaluated from monitoring corrosion environment data as the corrosion current, time of wetness, mean corrosion depth of each monitoring member. Additionally, the atmospheric corrosion environment monitoring was also conducted to compare with the local corrosion environment of steel box members. From these local corrosion environment monitoring for the steel box specimen, the relationship between the relative corrosion environment and mean corrosion depth of each steel box member was examined.