• 제목/요약/키워드: Research Background

검색결과 10,302건 처리시간 0.049초

Comparison of Normalization Methods for Defining Copy Number Variation Using Whole-genome SNP Genotyping Data

  • Kim, Ji-Hong;Yim, Seon-Hee;Jeong, Yong-Bok;Jung, Seong-Hyun;Xu, Hai-Dong;Shin, Seung-Hun;Chung, Yeun-Jun
    • Genomics & Informatics
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    • 제6권4호
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    • pp.231-234
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    • 2008
  • Precise and reliable identification of CNV is still important to fully understand the effect of CNV on genetic diversity and background of complex diseases. SNP marker has been used frequently to detect CNVs, but the analysis of SNP chip data for identifying CNV has not been well established. We compared various normalization methods for CNV analysis and suggest optimal normalization procedure for reliable CNV call. Four normal Koreans and NA10851 HapMap male samples were genotyped using Affymetrix Genome-Wide Human SNP array 5.0. We evaluated the effect of median and quantile normalization to find the optimal normalization for CNV detection based on SNP array data. We also explored the effect of Robust Multichip Average (RMA) background correction for each normalization process. In total, the following 4 combinations of normalization were tried: 1) Median normalization without RMA background correction, 2) Quantile normalization without RMA background correction, 3) Median normalization with RMA background correction, and 4) Quantile normalization with RMA background correction. CNV was called using SW-ARRAY algorithm. We applied 4 different combinations of normalization and compared the effect using intensity ratio profile, box plot, and MA plot. When we applied median and quantile normalizations without RMA background correction, both methods showed similar normalization effect and the final CNV calls were also similar in terms of number and size. In both median and quantile normalizations, RMA backgroundcorrection resulted in widening the range of intensity ratio distribution, which may suggest that RMA background correction may help to detect more CNVs compared to no correction.

Determination of the Uranium Backgrounds in Lexan Films for Single Particle Analysis using FT-TIMS technique

  • Park, Su-Jin;Park, Jong-Ho;Lee, Myung-Ho;Song, Kyu-Seok
    • Mass Spectrometry Letters
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    • 제2권2호
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    • pp.57-60
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    • 2011
  • As background significantly affects measurement accuracy and a detection limit in determination of the trace amounts of uranium, it is necessary to determine the impurities in the Lexan detector film for single particle measurements by thermal ionization mass spectrometry coupled with fission track technique (FT-TIMS). We have prepared various micro sizes of the blank Lexan detector film using a micromanipulation technique for uranium measurements by TIMS. Few tens of fg of uranium background with no remarkable dependency on the film sizes were observed in the blank Lexan films with the sizes from $50{\times}50\;{\mu}m^2$ to $300{\times}300\;{\mu}m^2$. Based on the determination of the uranium background in the Lexan film, any background correction is necessary in the isotopic analysis of a uranium single particle with micron sizes when the particle bearing Lexan film is dissected with less than $300{\times}300\;{\mu}m^2$ size. The isotopic analysis of a uranium particle in U030 standard material using TIMS was carried out to verify the applicability of the Lexan film to the single particle analysis with high accuracy and precision.

유통점의 배경음악에 관한 연구 (Study on Background Music of Distributors)

  • 이준표;황희중
    • 유통과학연구
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    • 제17권9호
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    • pp.127-131
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    • 2019
  • Purpose - This study focuses on clues that can clearly amplify the effects of background music. Review which store environments have a direct and positive impact on consumer responses, such as purchases. Research design, data, and methodology - This study focuses on clues that can clearly amplify the effects of background music. The purpose of this study is to examine what kind of store environment, combined with background music, has a direct and positive effect on consumer reactions such as purchase, and suggest future research directions. Results - The manager decides to use background music in the store because it is relatively inexpensive and easy to identify the emotional response of the consumer. In addition, appropriate background music lowers the psychological purchasing barriers of consumers. Previous studies have often not conducted a basic review of whether consumers perceive background music when it is used in retail stores. For example, it is necessary to make sure that the volume of the background music is loud enough and that the noise is properly excluded despite the congestion of the store so that the pure influence of the background music on the consumer can be measured. A way for store managers to clarify and differentiate their identity is to create a unique and satisfying store atmosphere for their customers. In order to help customers focus on their purchases, store managers must use marketing elements to integrate the five senses. And they should plan background music aiming at synergy effect of these five senses. In other words, in order to make the store atmosphere positive, it is not enough to have a suitable visual design interior or background music in the store, and consumers should have the opportunity to smell, taste and touch it directly. Conclusions - In conclusion, we hope that the following issues will be studied by several scholars in the future. It should be clarified that the impact of background music on customers varies depending on the customer's movement in the store, the selection of the background music genre order, and the timing (interval) of background music exposure to the customer.

배경제거 가산투영 방법을 이용한 근거리 해상 표적 탐지 (Close Surface Targets Detection using Background Removal Integral Projection in Coastal Environment)

  • 이부환;김지은;양유경
    • 한국군사과학기술학회지
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    • 제17권1호
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    • pp.115-121
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    • 2014
  • In this paper, we propose a robust background removal integral projection(BRIP) method which can detect close surface targets in coastal environment for IRST. Row pixels of background region from coastal infrared image show similar response. Thus, the proposed BRIP is calculated after horizontal and vertical background estimations and removals are performed sequentially. Finally, surface large targets can be detected using the results of the BRIP. Experimental results on a set of real infrared image sequence show that the proposed method could fully detect ships in every frame.

한·중·일 PM10 국가 배경농도 최근 경향 분석 (Analysis of the Recent Trend of National Background PM10 Concentrations over Korea, China, and Japan)

  • 양금희;이종재;유영숙;장임석;임재현;이동원;김상균;김철희
    • 한국대기환경학회지
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    • 제32권4호
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    • pp.360-371
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    • 2016
  • The goal of this research is to examine the recent decade-long (2000~2014) trends of national background concentrations over China, Japan, and Korea. Based on the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project, which is three-party collaboration project among three countries, we investigated the long-term trends of national background $PM_{10}$ concentrations in three countries over the recent 15 years, including the 2008 Beijing Olympic Game period. In accordance with the agreement among three countries, a total of 8 national background sites: three national background monitoring sites in China (2 sites in Dalian, and 1 in Xiamen), three sites in Korea (Ganghwa, Gosan, and Taean), and two sites in Japan (Oki and Rishiri), were chosen for the trend analysis. The results showed that Chinese background concentration recorded the highest level overall. However, the rapid declining recent trends of annual median ($50^{th}$-percentile) values were surprisingly detected since 2006 or 2007 in every site in China, with the most rapidly decreasing rate (- $18.6{\pm}10.3%$/year) over 2006~2007, and the second most rapidly decreasing rate (- $18.0{\pm}1.5%$/year) over 2007~2008. Based on the previous statistical literature, we concluded that this declining trends were due to the emission reduction of $PM_{10}$ concentrations in China for 2008 Beijing Olympic Game. In Korea, Ganghwa was also showing the decreasing trends over the recent years since 2006, which is also well accorded with the decreasing period of Chinese background concentrations. Taean also implied some impact of Beijing Olympic Game, showing small but detectable decreasing trends, while Gosan showed the increasing tendencies probably due to the near-urban influences. However, since 2012, most sites in both China and Korea showed strong increasing trends, undoubtedly implying the increasement of both emission in China and its long-range transport process toward Korea. Two sites in Japan, Oki and Rishiri recorded the lowest level of $PM_{10}$ level during whole period with the smallest deviations of measurements. Other discussions including the decade-long trends of $5^{th}$, $10^{th}$, $25^{th}$, $50^{th}$, $75^{th}$, $90^{th}$, $95^{th}$-percentiles of $PM_{10}$ background concentrations in three countries were also comparatively addressed here.

TiO2 제조 실험실에서 나노입자의 배경농도 특징 (Characteristics of Background Nanoparticle Concentration in a TiO2 Manufacturing Laboratory)

  • 박승호;정재희;이승복;배귀남;지현석;조소혜
    • 한국입자에어로졸학회지
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    • 제7권4호
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    • pp.113-121
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    • 2011
  • The aerosol nanoparticles are suspected to be exposed to workers in nanomaterial manufacturing facilities. However, the exposure assessment method has not been established. One of important issues is to characterize background level of nanoparticles in workplaces. In this study, intensive aerosol measurements were made at a $TiO_2$ manufacturing laboratory for five consecutive days in May of 2010. The $TiO_2$ nanoparticles were manufactured by the thermal-condensation process in a heated tube furnace. The particle number size distribution was measured using a scanning mobility particle sizer every 5 min, in order to detect particles ranging from 14.5 to 664 nm in diameter. Total particle number concentration shows a severe diurnal variation irrespective of manufacturing process, which was governed by nanoparticles smaller than 50 nm in diameter. During the background monitoring periods, significant peak concentrations were observed between 2 p.m. and 3 p.m. due to the infiltration of secondary aerosol particles formed by photochemical smog. Although significant increase in nanoparticle concentration was also observed during the manufacturing process twice among three times, these particle peak concentrations were lower than those observed during the background measurement. It is suggested that the investigation of background particle contamination is needed prior to conducting main exposure assessment in nanomaterial manufacturing workplaces or laboratories.

Measurement of Solar Cell Using LED-based Differential Spectral Responsivity Comparator under High Background Irradiance

  • Zaid, Ghufron;Park, Seong-Chong;Lee, Dong-Hoon;Park, Seung-Nam
    • 한국광학회:학술대회논문집
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    • 한국광학회 2009년도 동계학술발표회 논문집
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    • pp.293-294
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    • 2009
  • The spectral responsivity of solar cells has been measured under high background irradiance using an LED-based differential spectral responsivity Comparator (DSR-C). The comparator developed is fully automated and has some advantages: It does not need a chopper to modulate the light. Unlike the conventional method, it does not require a monochromator to select wavelength. It covers a wavelength range up to 1200 nm. The wavelength range of the comparator is limited by the spectral power distribution of the LEDs and the spectral responsivity of the standard detector. An active temperature control was utilized to meet the specified standard conditions of solar cell test. This work shows the effect of different levels of background irradiance on the spectral responsivity and the importance of same background irradiance for solar cell test as specified by the corresponding standard.

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Background memory-assisted zero-shot video object segmentation for unmanned aerial and ground vehicles

  • Kimin Yun;Hyung-Il Kim;Kangmin Bae;Jinyoung Moon
    • ETRI Journal
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    • 제45권5호
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    • pp.795-810
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    • 2023
  • Unmanned aerial vehicles (UAV) and ground vehicles (UGV) require advanced video analytics for various tasks, such as moving object detection and segmentation; this has led to increasing demands for these methods. We propose a zero-shot video object segmentation method specifically designed for UAV and UGV applications that focuses on the discovery of moving objects in challenging scenarios. This method employs a background memory model that enables training from sparse annotations along the time axis, utilizing temporal modeling of the background to detect moving objects effectively. The proposed method addresses the limitations of the existing state-of-the-art methods for detecting salient objects within images, regardless of their movements. In particular, our method achieved mean J and F values of 82.7 and 81.2 on the DAVIS'16, respectively. We also conducted extensive ablation studies that highlighted the contributions of various input compositions and combinations of datasets used for training. In future developments, we will integrate the proposed method with additional systems, such as tracking and obstacle avoidance functionalities.

Background Subtraction in Dynamic Environment based on Modified Adaptive GMM with TTD for Moving Object Detection

  • Niranjil, Kumar A.;Sureshkumar, C.
    • Journal of Electrical Engineering and Technology
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    • 제10권1호
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    • pp.372-378
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    • 2015
  • Background subtraction is the first processing stage in video surveillance. It is a general term for a process which aims to separate foreground objects from a background. The goal is to construct and maintain a statistical representation of the scene that the camera sees. The output of background subtraction will be an input to a higher-level process. Background subtraction under dynamic environment in the video sequences is one such complex task. It is an important research topic in image analysis and computer vision domains. This work deals background modeling based on modified adaptive Gaussian mixture model (GMM) with three temporal differencing (TTD) method in dynamic environment. The results of background subtraction on several sequences in various testing environments show that the proposed method is efficient and robust for the dynamic environment and achieves good accuracy.