• 제목/요약/키워드: Spectral Features

검색결과 437건 처리시간 0.024초

NEW DEVELOPMENT OF HYPERGAM AND ITS TEST OF PERFORMANCE FOR γ-RAY SPECTRUM ANALYSIS

  • Park, B.G.;Choi, H.D.;Park, C.S.
    • Nuclear Engineering and Technology
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    • 제44권7호
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    • pp.781-790
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    • 2012
  • The HyperGam program was developed for the analysis of complex HPGe ${\gamma}$-ray spectra. The previous version of HyperGam was mainly limited to the analysis of ${\gamma}$-ray peaks and the manual logging of the result. In this study, it is specifically developed into a tool for the isotopic analysis of spectra. The newly developed features include nuclide identification and activity determination. An algorithm for nuclide identification was developed to identify the peaks in the spectrum by considering the yield, efficiency, energy and peak area for the ${\gamma}$-ray lines emitted from the radionuclide. The detailed performance of nuclide identification and activity determination was accessed using the IAEA 2002 set of test spectra. By analyzing the test spectra, the numbers of radionuclides identified truly (true hit), falsely (false hit) or missed (misses) were counted and compared with the results from the IAEA 2002 tests. The determined activities of the radionuclides were also compared for four test spectra of several samples. The result of the performance test is promising in comparison with those of the well-known software packages for ${\gamma}$-ray spectrum analysis.

Ultraviolet Properties of Dwarf Galaxies in the Ursa Major Cluster

  • Pak, Min-A;Rey, Soo-Chang;Kim, Suk;Lee, Young-Dae;Yi, Won-Hyeong;Sung, Eon-Chang;Kyung, Jae-Mann
    • 천문학회보
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    • 제35권2호
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    • pp.41.2-41.2
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    • 2010
  • We present ultraviolet (UV) properties of dwarf galaxies in the Ursa Major cluster comparing with those in the Virgo cluster. We have constructed SDSS DR7/GALEX GR5 matched optical/UV catalog for dwarf galaxies with various morphologies in these two clusters. Membership of galaxies belonging to the Ursa Major cluster was made by hierarchical grouping method using SDSS spectroscopic data. We classified morphologies of dwarf galaxies using the combination of visual inspection of the images and spectral features returned from SDSS data. In contrast to the case of the Virgo cluster, majority of dwarf galaxies in the Ursa Major cluster lies in the blue cloud of the UV color-magnitude relations (CMRs) implying strong recent or on-going star formation. We discuss the cluster environment on the star formation history and evolution of dwarf galaxies.

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High-resolution Optical and Near-infrared Monitoring Observations of 2MASS J06593158-0405277

  • Park, Sunkyung;Lee, Jeong-Eun;Pyo, Tae-Soo;Sung, Hyun-Il;Lee, Sang-Gak;Kang, Wonseok;Yoon, Tae Seog;Park, Won-Kee
    • 천문학회보
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    • 제43권1호
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    • pp.65.3-66
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    • 2018
  • We present the results of high-resolution optical (R ~ 30,000) and near-infrared (R ~ 45,000) spectroscopic monitoring observations of a new FU Orionis-like young stellar object, 2MASS J06593158-0405277. FU Orionis objects (FUors) are well-studied examples of episodic accretion because of their outburst phenomenon. Recently, 2MASS J06593158-0405277 exhibited an outburst and was identified as a FUor. It provides an important opportunity to investigate the whole FUors phenomenon from its pre-outburst to its post-outburst phase. We monitored 2MASS J06593158-0405277 with the BOES and the IGRINS since Dec 25, 2014 (UT). We detected several wind and disk features and present here our analysis for time variations of those spectral lines.

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Survey of Electro-Optical Infrared Sensor for UAV

  • Jang, Seung-Won;Kim, Joong-Wook
    • 항공우주산업기술동향
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    • 제6권1호
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    • pp.124-134
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    • 2008
  • The rising demand for the high efficiency and high covertness in UAV motivates the miniature design of the high performing mission sensors, or payloads. One of the promising payload sensors, EO/IR sensor has evolved satisfying its demands and became the main stand-alone mission sensor for 200kg-range UAV. One aspect in development of EO/IR sensor concerns lack of specification criterions to represent its performance. Even though the high demand and competition among each manufacturer caused EO/IR features subject to rapid change collateral to new technology, the datasheets maintained the conventional outdated formats which leave some of the major components in ambiguity. Making comparisons or predicting actual performance with such datasheets is hardly worthwhile; yet, they could be important reference guide for the potential customers what to expect for the upcoming EO/IR. According to UAS Roadmap 2007-2032 published by DoD, one of the main potential customers as well as a main investor of EO/IR technology, EO/IR is expected to play key roll in solving urgent problems, such as see and avoid system. This paper will examine the recent representative EO/IR specialized in UAS missions through datasheets to find out current trend and eventually extrapolate the possible future trend.

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연속적인 뇌파 분류를 위한 비음수 텐서 분해 (Nonnegative Tensor Factorization for Continuous EEG Classification)

  • 이혜경;김용덕;;최승진
    • 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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    • 제14권5호
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    • pp.497-501
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    • 2008
  • 본 논문에서는 연속적인 뇌파 분류를 위해 비음수 텐서 분해를 이용한 특징 추출과 비터비 알고리즘을 이용한 연속적인 데이타의 클래스 분류를 결합한 새로운 알고리즘을 제시한다. 비음수 텐서 분해는 이미 스펙트럼 데이타에 대해 뇌파의 주요한 특징을 잘 추출한다고 알려진 비음수 행렬 분해의 확장으로써 행렬이라는 제한된 틀에서 벗어나 데이타가 가지는 다양한 차원으로의 확대가 가능하다. 뇌-컴퓨터 인터페이스 컴피티션을 통해 공개된 데이터를 이용한 실험을 통해 제안된 방법의 유용함을 증명하도록 하겠다.

Atmospheric Correction Problems with Multi-Temporal High Spatial Resolution Images from Different Satellite Sensors

  • Lee, Hwa-Seon;Lee, Kyu-Sung
    • 대한원격탐사학회지
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    • 제31권4호
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    • pp.321-330
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    • 2015
  • Atmospheric correction is an essential part in time-series analysis on biophysical parameters of surface features. In this study, we tried to examine possible problems in atmospheric correction of multitemporal High Spatial Resolution (HSR) images obtained from two different sensor systems. Three KOMPSAT-2 and two IKONOS-2 multispectral images were used. Three atmospheric correction methods were applied to derive surface reflectance: (1) Radiative Transfer (RT) - based absolute atmospheric correction method, (2) the Dark Object Subtraction (DOS) method, and (3) the Cosine Of the Uun zeniTh angle (COST) method. Atmospheric correction results were evaluated by comparing spectral reflectance values extracted from invariant targets and vegetation cover types. In overall, multi-temporal reflectance from five images obtained from January to December did not show consistent pattern in invariant targets and did not follow a typical profile of vegetation growth in forests and rice field. The multi-temporal reflectance values were different by sensor type and atmospheric correction methods. The inconsistent atmospheric correction results from these multi-temporal HSR images may be explained by several factors including unstable radiometric calibration coefficients for each sensor and wide range of sun and sensor geometry with the off-nadir viewing HSR images.

색변환과 영상개선기법을 이용한 SPOT P-mode와 XS-mode 영상합성 (Merging of SPOT P-mode and XS-mode Images using Color Transformation and Image Enhancement)

  • 손덕재;이종훈
    • 한국측량학회지
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    • 제9권2호
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    • pp.103-113
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    • 1991
  • SPOT 수치영상자료를 이용한 지상좌표 계산 과정에서 지상기준점 및 검사점 입럭좌표의 정확도는 계산 결과의 신빙성에 커다란 영향을 준다. CRT 모니터상에 직접 나타난 SPOT 원초 영상은 일반적으로 지상물체의 판별과 점위치 결정에 적합하지 않으므로 전체영상의 대비개선, 영상소보간, 경계선강조, 공간필터처리 등 적절한 영상처리 기병의 적용이 필요하다. 본 연구에서는 대상지역의 3차원 위치 결정과 파장대특성분석에 이용되는 SPOT 위성영상의 시각분석에 필요한 수치영상처리기법의 원리를 고찰하고, 그 적용을 위한 알고리즘을 개발하여 프로그래밍 하였으며, 실제 P-mode 및 XS-mode의 SPOT 영상을 이용하여 고해상도 천연색영상인 SPOT P+XS 영상으로 합성하였다.

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Expression and Characterization of Truncated Recombinant Human Cytochrome P450 2J2

  • Park, Hyoung-Goo;Lim, Young-Ran;Han, Songhee;Kim, Donghak
    • Toxicological Research
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    • 제30권1호
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    • pp.33-38
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    • 2014
  • The human cytochrome P450 2J2 catalyzes an epoxygenase reaction to oxidize various fatty acids including arachidonic acid. In this study, three recombinant enzyme constructs of P450 2J2 were heterologously expressed in Escherichia coli and their P450 proteins were successfully purified using a $Ni^{2+}$-NTA affinity column. Deletion of 34 amino acid residues in N-terminus of P450 2J2 enzyme (2J2-D) produced the soluble enzyme located in the cytosolic fraction. The enzymatic analysis of this truncated protein indicated the typical spectral characteristics and functional properties of P450 2J2 enzyme. P450 2J2-D enzymes from soluble fraction catalyzed the oxidation reaction of terfenadine to the hydroxylated product. However, P450 2J2-D enzymes from membrane fraction did not support the P450 oxidation reaction although it displayed the characteristic CO-binding spectrum of P450. Our finding of these features in the N-terminal modified P450 2J2 enzyme could help understand the biological functions and the metabolic roles of P450 2J2 enzyme and make the crystallographic analysis of the P450 2J2 structure feasible for future studies.

Assessment of Agricultural Environment Using Remote Sensing and GIS

  • Hong Suk Young
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2005년도 국제학술회의
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    • pp.75-87
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    • 2005
  • Remote sensing(RS)- and geographic information system(GIS)-based information management to measure and assess agri-environment schemes, and to quantify and map environment indicators for nature and land use, climate change, air, water and energy balance, waste and material flow is in high demand because it is very helpful in assisting decision making activities of farmers, government, researchers, and consumers. The versatility and ability of RS and GIS containing huge soil database to assess agricultural environment spatially and temporally at various spatial scales were investigated. Spectral and microwave observations were carried out to characterize crop variables and soil properties. Multiple sources RS data from ground sensors, airborne sensors, and also satellite sensors were collected and analyzed to extract features and land cover/use for soils, crops, and vegetation for support precision agriculture, soil/land suitability, soil property estimation, crop growth estimation, runoff potential estimation, irrigated and the estimation of flooded areas in paddy rice fields. RS and GIS play essential roles in a management and monitoring information system. Biosphere-atmosphere interection should also be further studied to improve synergistic modeling for environment and sustainability in agri-environment schemes.

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Acoustic Signal based Optimal Route Selection Problem: Performance Comparison of Multi-Attribute Decision Making methods

  • Borkar, Prashant;Sarode, M.V.;Malik, L. G.
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제10권2호
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    • pp.647-669
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    • 2016
  • Multiple attribute for decision making including user preference will increase the complexity of route selection process. Various approaches have been proposed to solve the optimal route selection problem. In this paper, multi attribute decision making (MADM) algorithms such as Simple Additive Weighting (SAW), Weighted Product Method (WPM), Analytic Hierarchy Process (AHP) method and Total Order Preference by Similarity to the Ideal Solution (TOPSIS) methods have been proposed for acoustic signature based optimal route selection to facilitate user with better quality of service. The traffic density state conditions (very low, low, below medium, medium, above medium, high and very high) on the road segment is the occurrence and mixture weightings of traffic noise signals (Tyre, Engine, Air Turbulence, Exhaust, and Honks etc) is considered as one of the attribute in decision making process. The short-term spectral envelope features of the cumulative acoustic signals are extracted using Mel-Frequency Cepstral Coefficients (MFCC) and Adaptive Neuro-Fuzzy Classifier (ANFC) is used to model seven traffic density states. Simple point method and AHP has been used for calculation of weights of decision parameters. Numerical results show that WPM, AHP and TOPSIS provide similar performance.