• Journal of Radiation Protection and Research
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• 제23권2호
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• pp.65-74
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• 1998

저 준위방사능 계측에서 가장 기본적으로 요구되는 것이 최적 측정시간의 결정이다. 최적화된 계측전략으로 측정시간을 결정하기 위하여 측정시간을 고정하는 방법, 측정값을 고정하는 방법, 시료와 자연계수율 또는 기준준위를 비교하여 측정하는 방법을 비교 검토하는 결정식을 도출하였다. 이 계측전략에서 기기에 주어진 측정조건 즉, 검출기의 효율, 측정기의 용량, 측정기의 최대 및 평균 자연계수율과 관련기준 즉, 기준준위, 검출한계 등을 만족하는 측정시간이 결정된다. 계측전략은 측정시 주어진 조건에서 방사능 존재확인과 정량분석에 대한 시료의 최적 측정시간의 결정을 편리하게 함으로써 일상의 저준위방사능 측정에 유용하게 사용될 것이다.

• 센서학회지
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• 제30권4호
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• pp.236-242
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• 2021

In this paper, we report the fabrication of the tip-on-gate of a field-effect-transistor (ToGoFET) probe using a standard complementary metal-oxide-semiconductor (CMOS) process and the performance evaluation of the fabricated probe. After the CMOS process, I-V characteristic measurement was performed on the reference MOSFET. We confirmed that the ToGoFET probe could be operated at a gate voltage of 0 V due to channel ion implantation. The transconductance at the operating point (Vg = 0 V, Vd = 2 V) was 360 ㎂/V. After the fabrication process was completed, calibration was performed using a pure metal sample. For sensitivity calibration, the relationship between the input voltage of the sample and the output current of the probe was determined and the result was consistent with the measurement result of the reference MOSFET. An oxide sample measurement was performed as an example of an application of the new ToGoFET probe. According to the measurement, the ToGoFET probe could spatially resolve a hundred nanometers with a height of a few nanometers in both the topographic image and the ToGoFET image.

• 한국광학회:학술대회논문집
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• 한국광학회 2002년도 제13회 정기총회 및 2002년도 동계학술발표회
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• pp.42-43
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• 2002

• 한국전자파학회논문지
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• 제14권9호
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• pp.955-960
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• 2003

본 논문에서는 이동 가능한 프로브(probe)가 있는, 종단된 동축 슬롯 선로(Coaxial slotted line)를 샘플 液의 흘더로 사용하여, 이동 통신 단말기 의 송신 주파수帶에서의 복소 유전율을 측정할 수 있는 시스템을 제작하였으며, 이를 이용하여 IEEE Std 1528-200X에 서 제안한 기준 액체들(Reference Liquids)의 복소 유전율을 측정 비교하여 봄으로써, 측정 시스템의 타당성을 조사하였다.

• Nuclear Engineering and Technology
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• 제48권2호
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• pp.299-303
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• 2016

Prompt gamma activation analysis using a thermal neutron-guided beam at Japan Atomic Energy Agency JRR-3M was applied for the precise determination of Si in silicon nitride ceramic reference materials [Japan Ceramic Reference Material (JCRM) R 003]. In this study, the standard addition method coupled with internal standard was used for the nondestructive determination of Si in the sample. Cadmium was used as internal standard to obtain the linear calibration curves and to compensate for the neutron beam variability. The analytical result of determining Si in JCRM R 003 silicon nitride fine powder ceramic reference materials using prompt gamma activation analysis was in good agreement with that obtained by classical gravimetric analysis. The relative expanded measurement uncertainty (k = 2) associated with the determined value was 2.4%.

• 한국문헌정보학회지
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• 제21권
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• pp.141-168
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• 1991

The Purpose of this study is to explore and analyse ways of enhancing the effectiveness of reference service through reference evaluation. Marketing research technique combined with pre-evaluation theory was applied in this study to find out information for practice the service based on current concept of reference service. Aims and results of this study can be summarised as follows: First, the evaluation of effectiveness of reference service should be conducted for the purpose of finding out the ways of increasing user's satisfaction. Second, the policy evaluation was understood as the appropriated evaluation concept. The policy evaluation in principle coincides with reference service in sense that the satisfaction of public should have priority and hence be the criterion of the evaluation. Third, marketing research based on recently developed 'marketing concept', which concentrates all its efforts to meet user's demand and attempt to acquire the information for better marketing management of non-profit organization such as library, is examined to find out the evaluation method practically applicable to the pre-evaluation of reference service. In this study , conjoint analysis was adopted as the method of pre-evaluation about reference service. The Reference Room of the Central Library Yonsei University, was selected as the arget sample to find out the expected condition for the maximization of the user's satisfaction from the reference service. Based on this example study, the analysis indicates as the most desirable combination for reference service in terms of the user's satisfaction is following condition: the younger librarian with aimable personality who displays willingness In his/her assistance, plus as the method of reference service, sufficient and practical introduction to the reference materials available, plus immediate and satisfactory result of the service, and finally a library equipped with inter-library use system.

• Asian-Australasian Journal of Animal Sciences
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• 제33권2호
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• pp.332-338
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• 2020

Objective: Aim of this study was to evaluate the influence of freeze-dried acid whey addition and the use a game meat (fallow deer) on a microbial content and the biogenic amines formation in dry fermented sausages. Methods: The experiment involved dry fermented sausages made in two variants from beef and from fallow deer. Each variant was divided into five groups: control (with a curing mixture), reference (with a sea salt), sample with a liquid acid whey and two samples with the addition of reconstituted freeze-dried acid whey in different concentrations. Changes in lactic acid bacteria (LAB), Enterobacteriaceae content and biogenic amines content were determined. Results: The microbial content changes suggest that addition of acid whey slightly affected LAB content in comparison with the control and reference sample, but the addition of freezedried acid whey resulted in a reduction of Enterobacteriaceae content in the sausages from fallow deer or a similar level in the beef sausages compared with the control and reference sample. Both changes in LAB and Enterobacteriaceae content were more evident in case of sausages made from fallow deer. Addition of acid whey (liquid and a higher amount of freezedried) and use of fallow deer meat to produce the sausages resulted in a significant reduction of total biogenic amines content. Conclusion: The addition of acid whey (liquid and higher amount of freeze-dried) resulted in a significant reduction of total biogenic amines content in dry fermented sausages made from fallow deer meat.

• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.737-744
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• 2007

An isotope dilution-liquid chromatography/tandem mass spectrometric method was developed as a candidate reference method for the accurate determination of acrylamide in potato chips, starch-rich foodstuff cooked at high temperature. Sample was spiked with 13C3-acrylamide and then extracted with water. The extract was further cleaned up with an Oasis HLB solid-phase extraction (SPE) cartridge and an Oasis mixed-phase cation exchange (MCX) SPE cartridge. The extract was analyzed by using LC/ESI/Tandem MS in positive ion mode. LC with a medium reversed-phase (C4) column was optimized to obtain adequate chromatographic retention and separation of acrylamide. MS was operated to selectively monitor [M+H]+ ions of the analyte and its isotope analogue at m/z 72 and m/z 75, respectively. Sample was also analyzed by the LC/MS with selectively monitoring the collisionally induced dissociation channels of m/z 72 → m/z 55 and m/z 75 → 58. Compared to the LC/MS chromatograms, the LC/MS/MS chromatograms showed substantially reduced background chemical noises coming from solvent clusters formed during ESI spray processes and interferences from sample matrix. Repeatability and reproducibility studies showed that the LC/MS/MS method is a reliable and reproducible method which can provide a typical method precision of 1.0% while the LC/MS results are influenced by chemical interferences.

• 방사성폐기물학회지
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• 제17권4호
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• pp.363-373
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• 2019

Waste characterisation associated with nuclear site decommissioning relies on radiochemical analysis of a diverse range of sample types, requiring extensive validation of analytical techniques using matrix-matched materials. The absence of relevant reference materials has hindered robust method development and validation. The paper discusses how method validation in support of nuclear waste characterisation can be achieved without using reference materials. The key stages in an analytical procedure are evaluated and a multi-stage approach is proposed with the ultimate aim of determining an operational envelope for an analytical procedure.

• 한국산업보건학회지
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• 제4권1호
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• pp.103-116
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• 1994

This study was conducted to evaluate accuracy and precision of reference values used for quality control of the Korean industrial hygiene laboratory for three rounds. Factors affecting on accuracy and precision, including analytical procedures, were investigated. The results are summarized as follows. 1. Pooled relative standard deviation of reference values analyzed by reference laboratories was 2.01-5.91%, and that by both reference laboratories and participated laboratories was 3.18-6.63%. Better results were obtained when results of reference laboratories were employed. 2. Significant relationship was indicated between analytical precision and concentration of materials in samples. Variation increased by decreasing sample concentration. 3. Recoveries of lead and cadmium were about 98.6% and 99.8% respectively. There was a significant difference between lead values with and without recovery correction. 4. Organic solvent results corrected by desorption efficiency only and those corrected by Both internal standards and desorption efficiency were more accurate than those uncorrected. But, the latter was the best.