• 제목/요약/키워드: Large data

검색결과 14,138건 처리시간 0.044초

초대형 컨테이너선의 경하중량 추정을 위한 통계적 방법 연구 (A Study on Statistical Methods for the Light Weight Estimation of Ultra Large Container Ships)

  • 조용진
    • 한국해양공학회지
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    • 제23권3호
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    • pp.14-19
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    • 2009
  • The present study developed a model to estimate the light weight of an ultra-large container ship. The weight estimation model utilized container ship data obtained from shipyards and the subdivided this weight data into appropriate weight groups. Parameters potentially affecting the group weight were selected and expanded based on experience for weight estimation, and a correlation analysis was performed by the SPSS program to determine the key parameters characterizing the group weight. A weight estimation model applying the multi-regression analysis was proposed to assess the weight of an ultra-large container ship at the preliminary design stage, and the results obtained by the suggested method showed good agreement with the shipyard data.

AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD

  • Shimonishi, T.;Kato, D.;Ita, Y.;Onaka, T.;AKARI/IRC LMC team
    • 천문학논총
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    • 제32권1호
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    • pp.83-85
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    • 2017
  • We conducted an unbiased near- to mid-infrared imaging and spectroscopic survey of the Large Magellanic Cloud (LMC) as a part of the AKARI Mission Program "Large-area Survey of the LMC" (LSLMC, PI: T. Onaka). An area of about 10 square degrees of the LMC was observed by five photometric bands (3.2, 7, 11, 15, and $24{\mu}m$) and a low-resolution slitless prism ($2-5{\mu}m$, R ~20) equipped with AKARI /IRC. We constructed and publicly released photometric and spectroscopic catalogues of point sources in the LMC based on the survey data. The catalogues provide a large number of near-infrared spectral data, coupled with complementary broadband photometric data. Combined use of the present AKARI LSLMC catalogues with other infrared point source catalogues of the LMC possesses scientific potential that can be applied to various astronomical studies.

APPLICATION OF SATELLITE IMAGERY FOR DROUGHTS MONITORING IN LARGE AREA

  • Shin Sha-Chul;Jeong Soo;Kim Kyung-Tak;Kim Joo-Hun;Park Jung-Sool
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.398-401
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    • 2005
  • Droughts have been an important factor in disaster management in Korea because she has been grouped into nations of lack of water. Satellite imagery can be applied to droughts monitoring because it can afford periodic data for large area for long time. This study aims to develop a method to analyze droughts in large area using satellite imagery. We estimated evapotranspiration in large area using NDVI data acquired from satellite imagery. For satellite imagery, we dealt with MODIS data operated by NASA. As the result of this study, we improved the usability of satellite imagery, especially in drought analysis.

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광역의 가뭄 분석을 위한 위성영상의 활용 (The Application of Satellite Imagery in Droughts Analysis of Large Area)

  • 정수;신사철
    • 대한공간정보학회지
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    • 제14권2호
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    • pp.55-62
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    • 2006
  • 현재 물부족 국가로 분류되고 있는 우리나라 현실에서 가뭄은 재해 관리에 있어서 중요한 요소가 되고 있다. 위성영상은 광역의 지표면에 대해 오랜 시간 동안 주기적으로 자료를 취득할 수 있게 해주므로, 이를 가뭄의 관측에 활용하면 유용한 결과를 얻을 가능성이 크다. 본 연구에서는 광역의 가뭄현상을 해석하는 데 있어서 위성영상을 활용하는 방안을 제시하고자 하였다. 따라서, 미국 NASA에서 제공하는 MODIS 자료의 식생지수(NDVI)자료를 이용하여 광역의 증발산량을 산정하는 방법을 개발하였다. 위성영상을 이용하여 산정된 증발산량 분포를 강우 분포자료 및 잠재증발산량 분포자료와 결합하여 기후학적 물수지를 산정하였으며, 이를 기반으로 대상지역의 가뭄을 효과적으로 분석할 수 있었다. 본 연구의 결과는 가뭄 해석에 있어서의 위성영상의 활용도를 높이는 데 기여를 할 것이다.

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Aquaporin 4 expression is downregulated in large bovine ovarian follicles

  • Kim, Chang-Woon;Choi, Eun-Ju;Kim, Eun-Jin;Siregar, Adrian S.;Han, Jaehee;Kang, Dawon
    • 한국동물생명공학회지
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    • 제35권4호
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    • pp.315-322
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    • 2020
  • Aquaporin channels (AQPs) are known to play an important role in the development of ovarian follicles through their function in water transport pathways. Compared to other AQPs, research on the role of AQP4 in female reproductive physiology, particularly in cattle, remains limited. In our previous study, gene chip microarray data showed a downregulation of AQP4 in bovine cystic follicles. This study was performed to validate the AQP4 expression level at the protein level in bovine follicles using immunohistochemistry, Western blotting, and immunoprecipitation assays. Immunostaining data showed that AQP4 was expressed in granulosa and theca cells of bovine ovarian follicles. The ovarian follicles were classified according to size as small (< 10 mm) or large (> 25 mm) in diameter. Consistent with earlier microarray data, semi-quantitative PCR data showed a decrease in AQP4 mRNA expression in large follicles. Western blot analysis showed a downregulation of the AQP4 protein in large follicles. In addition, AQP4 was immunoprecipitated and blotted with anti-AQP4 antibody in small and large follicles. Accordingly, AQP4 exhibited a low expression in large follicles. These results show that AQP4 is downregulated in bovine ovarian large follicles, suggesting that the downregulation of AQP4 expression may interfere with follicular water transport, leading to bovine follicular cysts.

Selective Encryption Algorithm Based on DCT for GIS Vector Map

  • Giao, Pham Ngoc;Kwon, Gi-Chang;Lee, Suk-Hwan;Kwon, Ki-Ryong
    • 한국멀티미디어학회논문지
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    • 제17권7호
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    • pp.769-777
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    • 2014
  • With the rapid interest in Geographic Information System (GIS) contents, a large volume of valuable GIS dataset has been distributed illegally by pirates, hackers, or unauthorized users. Therefore the problem focus on how to protect the copyright of GIS vector map data for storage and transmission. At this point, GIS security techniques focusing on secure network and data encryption have been studied and developed to solve the copyright protection and illegal copy prevention for GIS digital map. But GIS vector map data is very large and current data encryption techniques often encrypt all components of data. That means we have encrypted large amount of data lead to the long encrypting time and high complexity computation. This paper presents a novel selective encryption scheme for GIS vector map data protection to store, transmit or distribute to authorized users using K-means algorithm. The proposed algorithm only encrypts a small part of data based on properties of polylines and polygons in GIS vector map but it can change whole data of GIS vector map. Experimental results verified the proposed algorithm effectively and error in decryption is approximately zero.

Data Reduction Method in Massive Data Sets

  • Namo, Gecynth Torre;Yun, Hong-Won
    • Journal of information and communication convergence engineering
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    • 제7권1호
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    • pp.35-40
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    • 2009
  • Many researchers strive to research on ways on how to improve the performance of RFID system and many papers were written to solve one of the major drawbacks of potent technology related with data management. As RFID system captures billions of data, problems arising from dirty data and large volume of data causes uproar in the RFID community those researchers are finding ways on how to address this issue. Especially, effective data management is important to manage large volume of data. Data reduction techniques in attempts to address the issues on data are also presented in this paper. This paper introduces readers to a new data reduction algorithm that might be an alternative to reduce data in RFID Systems. A process on how to extract data from the reduced database is also presented. Performance study is conducted to analyze the new data reduction algorithm. Our performance analysis shows the utility and feasibility of our categorization reduction algorithms.

Test for Independence in Bivariate Weibull Model under Bivariate Random Censorship

  • Cho, Jang-Sik;Cho, Kil-Ho;Lee, Woo-Dong
    • Journal of the Korean Data and Information Science Society
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    • 제14권4호
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    • pp.789-797
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    • 2003
  • In this paper, we consider two components system which have bivariate weibull model with bivariate random censored data. We proposed large sample test for independence based on maximum likelihood estimator and relative frequency estimator, respectively. Also we derive asymptotic properties for the large sample tests and present a numerical study.

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Large Sample Tests for Independence in Bivariate Pareto Model with Censored Data

  • 조장식;이재만;이우동
    • 한국데이터정보과학회:학술대회논문집
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    • 한국데이터정보과학회 2003년도 춘계학술대회
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    • pp.121-126
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    • 2003
  • In this paper, we consider two-components system which the lifetimes follow bivariate pareto model with censored data. We develop large sample tests for testing independence between two-components. Also we present simulated study which is the test based on asymptotic normal distribution in testing independence.

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삼차원 스캐너와 가변 적층 쾌속조형공정을 이용한 대형 입체 형상의 쾌속 제작 : 러쉬모어산 기념물 제작 사례 (Rapid Fabrication of Large-Sized Solid Shape using 3D Scanner and Variable Lamination Manufacturing : Case Study of Mount Rushmore Memorial)

  • 이상호;김효찬;송민섭;박승교;양동열
    • 대한기계학회논문집A
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    • 제28권12호
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    • pp.1958-1967
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    • 2004
  • This paper describes the method to rapidly fabricate the large-sized physical model with the envelope model size of more than 600 mm${\times}$ 600 mm${\times}$ 600 mm using two type semi-automatic VLM-ST processes in connection with the reverse engineering technology. The fabrication procedure of the large-sized solid shape is as follows: (1) Generation of STL data from 3D scan data using 3D scanner, (2) generation of shell-type STL data by Boolean operation, (3) division of shell-type STL data into several pieces by solid splitting, (4) generation of USL data for each piece with VLM-Slicer, (5) fabrication of each piece by cutting and stacking according to USL data using VLM-ST apparatus, (6) completion of a shell-type prototype by zigzag stacking and assembly for each piece, (7) completion of a 3D solid shape by foam backing, (8) surface finish of a completed 3D solid shape by coating and sanding. In order to examine the applicability of the proposed method, the miniature of the Mount Rushmore Memorial has been fabricated. The envelope model size of the miniature of the Mount Rushmore Memorial is 1,453 mm${\times}$ 760 mm${\times}$ 853 mm in size. From the result of the fabricated miniature of the Mount Rushmore Memorial, it has been shown that the method to fabricate the large object using two type semi-automatic VLM-ST processes in connection with the reverse engineering technology are very fast and efficient.