• Nuclear Engineering and Technology
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• 제50권6호
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• pp.929-936
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• 2018

A basic characterization of uranium samples was performed using gamma- and X-ray spectroscopy. The studied uranium samples were eight types of certified reference materials with $^{235}U$ enrichments in the range of 1-97%, and the measurements were performed over 24 h using a high-resolution and high-purity planar germanium detector. A general peak analysis of the spectrum and the $XK_{\alpha}$ region of the uranium spectra was carried out by using HyperGam and HyperGam-U, respectively. The standard reference sources were used to calibrate the spectroscopy system. To obtain the absolute detection efficiency, an effective solid angle code, EXVol, was run for each sample. Hence, the peak activities and isotopic activities were determined, and then, the total U content and $^{234}U$, $^{235}U$, and $^{238}U$ isotopic contents were determined and compared with those of the certified reference values. A new method to determine the model age based on the ratio of the activities of $^{223}Ra$ and $^{235}U$ in the sample was studied, and the model age was compared with the known true age. In summary, the present study developed a method for basic characterization of uranium samples by nondestructive gamma-ray spectrometry in 24 h and to obtain information on the sample age.

• 한국통신학회논문지
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• 제21권7호
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• pp.1633-1641
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• 1996

In this paper we propose a new method for anlayzing the properties of surface reflectance and reconstructing the shape of object using estimated reflectance parameters. We have investigated the hybrid reflectance surface which has specularreflection and diffuse reflection, which can be explained by Torrance-Sparrow model. Sample sphere made on one maerial is used to estimate the reflectance properties by using LMS algorithm. We can make the reference image which consists of surface normal and brightness value using estimated reflectance parameters, and thenarbitrary shape object made of the same material as sample can be reconstructed by matching with reference image. Photometric matching method proposed in this paper is robust because it mateches object image with the reference imageconsidering its neighbor brightness distribution. Also, in this paper plate diffuse illumination is used to remove intensity disparity with simple scheme. It is expected that the proposed algorithm can be applied to 3D recognition, vision inspection system and other fields.

• 한국물환경학회지
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• 제31권1호
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• pp.49-54
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• 2015

Acute toxicity test with Daphnia magna has a variety of factors such as incubation condition of test species, food quality and proficiency of laboratory workers. Therefore, proper proficiency testing samples were required for evaluating the competence of laboratory workers. This study aims to propose some appropriate proficiency testing samples for laboratory workers of acute toxicity test with Daphnia magna. Proposed four kinds of standard samples (Sample A, B, C, and D) for proficiency testing were selected from reference materials which were recommended from Canada and USA WET(Whole Effluent Toxicity) authorities. Proposed standard samples were tested by trial application of proficiency testing, homogeneity and stability checks using repeatability test. Sample A, C and D were estimated ad the suitable candidates for proficiency test standard samples except for Sample B. In addition, Sample A was proved to be the most suitable sample.

• Bulletin of the Korean Chemical Society
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• 제19권7호
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• pp.766-770
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• 1998

On-line preconcentration by direct precipitation with hydroxide has been developed and applied for the analysis of Cd in Inductively Coupled Plasma Atomic Emission Spectrometry. Cadmium is continuously precipitated with hydroxide and dissolved by nitric acid in on-line mode. Currently, the enrichment factor is more than 90 times for 20.0 mL of sample and could be further increased very easily. For a large sample throughput, 1.0 mL of sample loop is used and the enrichment factor is 4.5 with the sampling speed of 15/hr. The method has been applied to the analysis of NIST reference sample and has yielded good results with the certified value.

• 광물과 암석
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• 제33권1호
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• pp.65-71
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• 2020

유리 표준물질은 정밀 지구화학 분석법에 필수적으로 이용되는 표준물질이다. 기존의 합성 유리 표준물질의 단점인 자연 암석과의 조성 차이로 인한 높은 불확실성을 보완하기 위해, 자연산 암석을 이용하여 유리 표준물질을 제작하였다. 백두산 흑요암인 NK-B1G 시료는 미세결정이나 포유물 등의 결정을 포함하지 않는 자연 유리질 암석으로, EPMA나 LA-ICPMS 분석 등의 미세분석을 위한 표준물질로서의 적합성을 확인하였다.

• 제어로봇시스템학회논문지
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• 제6권1호
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• pp.57-65
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• 2000

In this paper, a model reference adaptive control for the atomic force microscope (AFM) of tapping mode is investigated. The dynamics between the AFM system and al sample is mathematically modeled as a second order spring-mass-damper system with oscillatory inputs. The attractive and repulsive forces between the tip of the AFM system and the sample are derived using the Lennard-Jones potential energy. By non-dimensionalizing the displacement of the tip and the input frequency, the chaotic behavior near a resonance frequency is better depicted through the non-dimensionalized equations. Four nonlinear analysis techniques, a phase portrait, sensitive dependence on initial conditions, a power spectral density function, and a Pomcare map are investigated. Because the equations of motion derived in this paper involve unknown parameter values such as the damping effect of the air and the interaction constants between materials, the standard model reference adaptive control is adopted. Two control objectives, the prevention of chaos and the tracking of reference signal, are pursued. Simulation results are included.

• 한국문헌정보학회지
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• 제32권2호
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• pp.121-142
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• 1998

온라인정보기술 환경이 참고봉사에 어떤 특성과 변화를 가져오는지를 구체적으로 검토하였다. 선행연구 결과를 바탕으로 고찰하였으며, 경우에 따라 국내 도서관의 사례조사도 실시하였다. 다음으로 이러한 특성과 변화가 이용자에 대한 참고사서의 기본적 중재역할인 정보제공, 교육, 상담, 평가 기능에 어떻게 영향을 미치게되는지 분석하였다. 변화된 상황에서 참고사서의 사명에 대한 개념적 기반을 보다 명백히하고 새롭게 확인된 역할을 실행하기 위해 필요한 자질을 재고해 보는데 본 논고의 궁극적 의의가 있다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 춘계학술대회 논문집
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• pp.7-14
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• 2006

Detection and identification of targets from remotely sensed imagery are of great interest for civilian and military application. This paper presents an algorithm for target detection in high spatial resolution imagery based on the spectral and the dimensional characteristics of the reference target. In this algorithm, the spectral and the dimensional information of the reference target is extracted automatically from the sample image of the reference target. Then in the entire image, the candidate target pixels are extracted based on the spectral characteristics of the reference target. Finally, groups of candidate pixels which form isolated spatial objects of similar size to that of the reference target are extracted as detected targets. The experimental test results showed that even though the algorithm detected spatial objects which has different shape as targets if the spectral and the dimensional characteristics are similar to that of the reference target, it could detect 97.5% of the targets in the image. Using hyperspectral image and utilizing the shape information are expected to increase the performance of the proposed algorithm.

• 대한원격탐사학회지
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• 제22권1호
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• pp.41-47
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• 2006

Detection and identification of targets from remotely sensed imagery are of great interest for civilian and military application. This paper presents an algorithm for target detection in high spatial resolution imagery based on the spectral and the dimensional characteristics of the reference target. In this algorithm, the spectral and the dimensional information of the reference target is extracted automatically from the sample image of the reference target. Then in the entire image, the candidate target pixels are extracted based on the spectral characteristics of the reference target. Finally, groups of candidate pixels which form isolated spatial objects of similar size to that of the reference target are extracted as detected targets. The experimental test results showed that even though the algorithm detected spatial objects which has different shape as targets if the spectral and the dimensional characteristics are similar to that of the reference target, it could detect 97.5% of the targets in the image. Using hyperspectral image and utilizing the shape information are expected to increase the performance of the proposed algorithm.

• 농업과학연구
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• 제38권2호
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• pp.277-284
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• 2011

The compositions of health functional food products (HFFP; 18 products) containing gamma linolenic acid (GLA; $C_{18:3}$, n-6) and omega-3 fatty acids (EPA and DHA) were investigated. The contents of index components (especially, GLA and omega-3) in HFFPs were monitored by GC-FID analysis. Among the GLA products (sample No. 1~8), the content of GLA in most samples (except sample No.6) ranged from 8.04 to 9.98 g/100 g. These results were suitable for the reference standard (more 7.0 g/100 g) of HFF. In the omega-3 products (sample No. 10 and 15) derived from harp seal oil (HSO), the total contents of EPA and DHA were 14.21-15.98 g/100 g, respectively. These values were suitable for the reference standard (more 12.0 g/100 g) of HFF. Besides, among the omega-3 products (sample No.9, 11~14, 16~18) derived from fish oil, the total content of EPA and DHA ranged from 24.11 to 31.20 g/100 g. These results were suitable for the reference standard (more 18.0 g/100 g) of HFF. In the result of TLC analysis, the HFFPs of 18 were mainly composed of triacylglycerols (TAGs). The content of trans fatty acid in 18 HFFPs was detected in less than 0.30 g/100 g. For the detection of trans fatty acid, $^1H$-NMR (600 MHz) can be used because chemical shift of trans fatty acid was observed at 5.3 ppm in this study.