• 보존과학연구
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• 통권20호
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• pp.81-90
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• 1999

We performed the non-destructive analysis of objects excavated at the Tomb of Mich’un-ri in Ch’ung-won. We analysed components using of Energy Dispersive X-Ray Micro-Fluorescence Analyzer. Glass bead inlaid with silver was classified as K2O-CaO-SiO2 type of glass. Purity of silver inlaid in the surface was verified above 97%.All small ear-ring were made by rolling up gold broad to a bronze wick. The composition ratio of Au : Ag has significantly higher 87 : 11 than bigear-ring. As a result of composition analysis of a welded part with big ear-ring, it contained the more Cu, Hg contents and the less Au, Ag contents than the surface of big ear-ring.

• 해안과 해양
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• 제5권1호
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• pp.56-63
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• 2012

• 기술혁신학회지
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• 제22권2호
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• pp.265-281
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• 2019

경제가 성장하고 인터넷이 발전되면서 사람들의 경제형태와 소비는 많이 바뀌었다. 중국 알리바바 그룹은 모바일, 온라인, 오프라인, 인공지능을 결합한 플랫폼으로 약 28조의 매출을 창출하고 있다. 이는 1초에 약 25만건을 처리하는 수준이며, 2016년 대비 40% 증가했다. 이를 가능하게 한 핵심 기술은 소위 Data Technology라고 불리는 빅데이터와 클라우드 컴퓨팅이 융합된 기술이다. 기술의 발전속도에 비해 Data Technology에 관한 정확한 개념적 정의는 부족하다. 이에 본 논문은 빅데이터 분석기법인 TexTom을 활용하여 구글과 네이버의 최근 3개년(2015년 11월~2018년 11월) 신문기사를 데이터 마이닝 및 정제하여 'Data Technology' 키워드로 한정하여 관련 핵심 키워드를 도출하였다. 그 결과 빅데이터, O2O, 인공지능, 사물인터넷, 클라우드 컴퓨팅의 핵심 키워드 기술이 Data Technology와 관계가 있음을 알수 있었다. 본 연구의 분석결과는 향후 Data Technology 시대가 도래되면 참고할 수 있는 유용한 정보로 활용될 수 있다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1992년도 가을학술발표회 논문집
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• pp.121-130
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• 1992

Assessement of comsolidation characteristics of soft soil is very important in the project of soft soil improvement. In the design step, the consolidation characteristics of soil is determined by the laboratory tests (typically oedometer test), generally. But there is big differences between the condition of laboratory test and the condition of field(in situ). the differences results in the considerable difference between the predicted and measured consolidation behavior. This article analyzed the consolidation data of the "SOFT SOIL IMPROVEMENT PROJECT of the 2nd Namdong Industrial Complex at Inchon". The project was improving the road way net work in the 2nd Namdong Industrial Complex by preloading and sand pile method. Field instrumentation was performed at 10 points which consist of pneumatic piezometers, magnetic probe extensometers, inclinometers and electronic dipmeter. The results showed that there is big difference in the laboratory predicted consolidation behavior and field consolidadion behavior. Also there was big difference in the settlement behavior and pore pressure behavior. This article investigated the above factors by comparing the settlement, pore pressure and strength at different conditions.onditions.

• 천문학회보
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• 제38권1호
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• pp.65.2-65.2
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• 2013

A presence of a penumbra is one of the main properties of a mature sunspot, and its formation mechanism has been elusive due to a lack of observations that fully cover the formation process. Utilizing the New Solar Telescope at the Big Bear Solar Observatory, we observed the formation of a partial penumbra for about 7 hours simultaneously at the photospheric (TiO; $7057{\AA}$) and the chromospheric ($H{\alpha}$, $-1{\AA}$) spectral lines with high spatial and temporal resolution. From this uninterrupted, long observational sequence, we found that flux emergence under the stable chromospheric canopy fields resulted in penumbra formation, while emerging flux under the expanding chromospheric fields appeared as transient elongated granules. Based on these findings, we suggest a possible scenario for penumbra formation in which a penumbra forms when the emerging flux is constrained from continuing to emerge, but rather is trapped at the photospheric level by the overlying chromospheric canopy fields.

• International Journal of Contents
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• 제17권3호
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• pp.74-83
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• 2021

A location-aware algorithm is proposed in this study to optimize the system performance of distributed systems for processing big data with low data reliability and application performance. Compared with previous algorithms, the location-aware data block placement algorithm uses data block placement and node data recovery strategies to improve data application performance and reliability. Simulation and actual cluster tests showed that the location-aware placement algorithm proposed in this study could greatly improve data reliability and shorten the application processing time of I/O interfaces in real-time.

• 정보과학회 컴퓨팅의 실제 논문지
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• 제22권2호
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• pp.95-100
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• 2016

빅데이터, 클라우드 컴퓨팅 시대가 오면서 데이터 사용량이 점점 증가하고 있고 이러한 빅데이터를 신속히 처리하기 위한 시스템들이 개발되고 있다. 그 중 데이터를 저장하기 위한 시스템으로 분산 파일 시스템이 널리 사용되고 있다, 이러한 분산 파일 시스템 중에는 글러스터 파일 시스템(GlusterFS)이 있다. 또한 기술의 발달로 고성능 장비인 Nand flash SSD (Solid State Drive)의 가격이 하락함에 따라서 데이터센터로 도입이 증가되는 추세이다. 따라서 GlusterFS에서도 SSD를 도입하려고 하지만, GlusterFS는 하드디스크를 기반으로 설계되었기 때문에 SSD를 이용했을 시 구조적인 문제로 성능 저하가 발생하게 된다. 이러한 구조적인 문제점들에는 I/O-cache, Read-ahead, Write-behind Translator들이 있다. 랜덤 I/O에 장점이 있는 SSD에 맞지 않는 기능들을 제거함으로써, 4KB 랜덤 읽기의 경우 255%까지의 성능 향상 결과와, 64KB 랜덤 읽기의 경우 50%까지의 성능 향상 결과를 얻었다.

• International Journal of Internet, Broadcasting and Communication
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• 제13권1호
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• pp.180-186
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• 2021

In cloud computing service it is important to share the system resource among multiple instances according to user requirements. In particular, the issue of efficiently distributing I/O resources across multiple instances is paid attention due to the rise of emerging data-centric technologies such as big data and deep learning. However, it is difficult to evaluate the I/O resource distribution of a Linux container, which is one of the core technologies of cloud computing, since conventional I/O benchmarks does not support features related to container management. In this paper, we propose a new I/O performance benchmarking framework that can easily evaluate the resource distribution of Linux containers using existing I/O benchmarks by supporting container-related features and integrated user interface. According to the performance evaluation result with trace-replay benchmark, the proposed benchmark framework has induced negligible performance overhead while providing convenience in evaluating the I/O performance of multiple Linux containers.

• 한국세라믹학회지
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• 제25권4호
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• pp.309-314
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• 1988

In this study, the effect of the size of sintered body on resonant and filter characteristics in Pb(Sn1/2Sb1/2)O3-PbTiO3 piezo-electric system were investigated. The attenuation characteristics of ring-dot type and ladder type filter were also investigated. As the size of sintered body was decreased, the resonant characteristic(Fr, Fa) and the center frequency(Fo) were increased. As the poling field was increased, the Kp and bandwidth were increased. The big difference between rign-dot type and ladder type was the sharpness of bandwidth, selectivity and the movement of center frequency.

• 한국항만학회지
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• 제14권2호
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• pp.175-185
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• 2000

Today freeway is experiencing a severe congestion with incoming or outgoing traffic through freeway ramps during the peak periods. Thus, the purpose of this study is to identify the traffic characteristics, analyze the relationships between the traffic characteristics and finally construct the delay predictive models on the rap junctions of freeway with 70mph speed limit. From the traffic analyses, and model construction and verification for delay prediction on the ramp junctions of freeway, the following results were obtained : ⅰ) Traffic flow showed a big difference depending on the time periods. Especially, more traffic flows were concentrated on the freeway junctions in the morning peak period. ⅱ) The occupancy also showed a big difference depending on the time periods, and the downstream occupancy(Od) was especially shown to have a higher explanatory power for the delay predictive model construction on the ramp junctions of freeway. ⅲ) The delay-occupancy curve showed a remarkable shift based on the occupancies observed : O$\_$d/〈9% and O$\_$d/$\geq$9%. Especially, volume and occupancy were shown to be highly explanatory for delay prediction on the ramp junctions of freeway under O$\_$d/$\geq$9%, but lowly for delay prediction on the ramp junctions of freeway under O$\_$d/〈9%. Rather, the driver characteristics or transportation conditions around the freeway were thought to be a little higher explanatory for the delay prediction under O$\_$d/〈9%. ⅳ) Integrated delay predictive models showed a higher explanatory power in the morning peak period, but a lower explanatory power in the non-peak periods.