• 한국광학회지
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• 제21권2호
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• pp.46-52
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• 2010

본 논문에서는 양방향 반사율 분포함수의 이론과 제작된 측정시스템 및 측정불확도의 평가방법을 소개한다. (380~1500) nm의 분광 양방향 반사율 분포함수를 $(-75{\sim}75)^{\circ}$의 각도 범위에서 측정할 수 있는 측정시스템을 제작하였고, 상관관계가 있는 불확도 성분과 상관관계가 없는 불확도 성분으로 나누어 측정불확도를 평가하였다. 평가 결과, 제작된 양방향 반사율 분포함수 측정시스템의 상대확장불확도는 3% (k=2) 이하로 평가되었다.

• 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%.

• Earthquakes and Structures
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• 제3권1호
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• pp.17-35
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• 2012

Simplified equations for fundamental period of vibration of skeletal structures provided by most seismic design provisions suffer from the absence of any associated confidence levels and of any reference to their empirical basis. Therefore, such equations may typically give a sector of designers the false impression of yielding a fairly accurate value of the period of vibration. This paper, although not addressing simplified codes equations, introduces a set of mathematical equations utilizing the theory of error propagation and First-Order Second-Moment (FOSM) techniques to determine bounds on the relative error in theoretically calculated fundamental period of vibration of skeletal structures. In a complementary step, and for verification purposes, Monte Carlo simulation technique has been also applied. The latter, despite involving larger computational effort, is expected to provide more precise estimates than FOSM methods. Studies of parametric uncertainties applied to reinforced concrete frame bents - potentially idealized as SDOF systems - are conducted demonstrating the effect of randomness and uncertainty of various relevant properties, shaping both mass and stiffness, on the variance (i.e. relative error) in the estimated period of vibration. Correlation between mass and stiffness parameters - regarded as random variables - is also thoroughly discussed. According to achieved results, a relative error in the period of vibration in the order of 19% for new designs/constructions and of about 25% for existing structures for assessment purposes - and even climbing up to about 36% in some special applications and/or circumstances - is acknowledged when adopting estimates gathered from the literature for relative errors in the relevant random input variables.

• 대한임상검사과학회지
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• 제52권1호
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• pp.28-35
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• 2020

본 조사의 목적은 국민건강보험공단에서 공개한 '한국인 혈당 참조 표준'의 원자료를 이용하여 나이 그룹별 95% 분포 상한값과 하한값의 차를 조사하고 이 데이터들에 대한 평균값 변화와 산포 정도를 분석하는 것이다. 그리고 이 데이터를 이용하여 16개 행정구역 간 경향과 남녀간 차이를 분석하는 것이다. 또한 본 조사의 결과가 NHIS에서 제시한 상대표준불화도와 관련성이 있는지를 분석하였다. 본 조사에서 분석한 나이 그룹별 공복혈당의 95% 분포 상한값과 하한값의 차이를 이용한 산포성 분석에서는 행정구역별로 의미 있는 차이와 경향을 보여주었고, 남녀 평균치 간에서도 유의한 차이를 보여주었다(P<0.05). NHIS에서 발표한 공복 혈당 측정값의 남녀간 차이는 행정구역별, 나이그룹별 비교에서 모두 유의한 차이(P<0.001)를 보여 주어 남녀 간 혈당 참고치 재산정 필요성이 인정되었다. NHIS가 발표한 행정구역별 상대표준불확도와 본 조사에서 분석한 산포성 그리고 측정수와는 유의한 상관성이 관찰되지 않았다. 그러나 측정 평균치와는 높은 상관성을 보여주었다(R²=0.95). 또한 참조표준의 적용과 불확도 평가에 대한 추가적인 연구가 필요할 것으로 사료된다.

• 대한환경공학회지
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• 제30권11호
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• pp.1123-1131
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• 2008

본 연구는 대기 중 PM2.5의 미량금속 중 As을 중성자방사화분석법을 이용하여 분석할 때 발생되는 측정불확도를 ISO GUM 방법과 MCS 방법을 모두 적용하여 비교, 평가하였다. 불확도의 요인은 ISO GUM을 엄격하게 준용하여 파악하였으며 특정일에 채취된 PM2.5 내 As 농도에 대해 두 방법의 계산 결과가 4% 미만으로 크게 다르지 않는 것으로 나타났다. 연구기간 중 채취된 총 60개의 PM2.5 시료에 대해 As 농도의 확장불확도를 역시 MCS 방법을 이용하여 산출하였는데, 연구지역에서의 As의 개별 농도값에 대한 95% 신뢰구간의 확장불확도는 대부분 10%의 범위에서 존재하는 것으로 나타났다. 확장불확도에 대한 표준불확도 요인의 기여율은 계측통계오차(62.3%), 검출효율(18.5%), 시료 채취 시 유량(12.3%), flux 변동(2.3%), 특정감마선 방출률(1.8%) 등의 순으로 크게 나타났다.

• 한국산학기술학회논문지
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• 제21권9호
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• pp.338-344
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• 2020

불확실성에 대한 인내력 부족은 범불안장애 등 다양한 정신질환과 관련이 있는 것으로 알려져 있다. 하지만 이를 측정하는 척도(IUS: Intolerance of Uncertainty Scale, 이하 IUS)는 여러 연구에서 요인 구조가 다르게 나타나는 바, 본 연구에서는 IUS의 구인 타당도를 검증하고 요인 구조를 명확하게 하고자 하였다. 이를 위해 대학생 533명을 대상으로 자료를 수집하였고, 이 중 임의로 추출한 260명의 자료를 대상으로 탐색적 요인 분석한 결과, 3문항으로 구성된 전향적 요인과 5문항으로 구성된 억제적 요인의 2요인 구조가 적합한 것으로 나타났다. 또한 나머지 273명의 자료를 대상으로 확인적 요인분석과 상관 분석을 한 결과, 8문항 2요인의 구조모형의 적합도가 선행 연구에서 제시한 모형들에 비해 우수하게 나타났다(x²=37.699, TLI=0.951, CFI=0.969, RMSEA=.063, SRMR=.039). 아울러 걱정 및 불안, 우울 관련 측정 도구들과 유의미한 정적 상관을 보였다. 본 연구는 IUS의 구인 타당도를 검증하여 전향적 요인과 억제적 요인으로 구성됨을 확인하고, IUS-08를 제안하여 보다 정확하고 간략한 척도를 개발하였다는 점에서 의의가 있겠다.

• 농촌계획
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• 제23권4호
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• pp.153-168
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• 2017

The main objective of this study was to assess reference evapotranspiration based on multiple GCMs (General Circulation Models) and estimation methods. In this study, 10 GCMs based on the RCP (Representative Concentration Pathway) 4.5 scenario were used to estimate reference evapotranspiration. 54 ASOS (Automated Synoptic Observing System) data were constructed by statistical downscaling techniques. The meteorological variables of precipitation, maximum temperature and minimum temperature, relative humidity, wind speed, and solar radiation were produced using GCMs. For the past and future periods, we estimated reference evapotranspiration by GCMs and analyzed the statistical characteristics and analyzed its uncertainty. Five methods (BC: Blaney-Criddle, HS: Hargreaves-Samani, MK: Makkink, MS: Matt-Shuttleworth, and PM: Penman-Monteith) were selected to analyze the uncertainty by reference evapotranspiration estimation methods. We compared the uncertainty of reference evapotranspiration method by the variable expansion and analyzed which variables greatly influence reference evapotranspiration estimation. The posterior probabilities of five methods were estimated as BC: 0.1792, HS: 0.1775, MK: 0.2361, MS: 0.2054, and PM: 0.2018. The posterior probability indicated how well reference evapotranspiration estimated with 10 GCMs for five methods reflected the estimated reference evapotranspiration using the observed data. Through this study, we analyzed the overall characteristics of reference evapotranspiration according to GCMs and reference evapotranspiration estimation methods The results of this study might be used as a basic data for preparing the standard method of reference evapotranspiration to derive the water management method under climate change.

• 한국기후변화학회지
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• 제6권1호
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• pp.33-40
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• 2015

Forests are to be recognized as an important carbon sink under the UNFCCC that consist of above- and below-biomass, dead organic matter (DOM) such as dead wood and litter, and soil organic matter (SOM). In order to asses for DOM and SOM, however, it is relevant to land-use change matrices over last 20 years for each land-use category. In this study, a land-use change matrix was produced and its uncertainty was assessed using a point sampling technique with permanent sample plots in national forest inventory at Chungbuk province. With point sampling estimated areas at 2012 year for each land-use category were significantly similar to the true areas by given six land-use categories. Relative standard error in terms of uncertainty of land-use change among land-use categories ranged in 4.3~44.4%, excluding the other land. Forest and cropland covered relatively large areas showed lower uncertainty compared to the other land-use categories. This result showed that selected permanent samples in the NFI are able to support for producing land-use change matrix at a national or province level. If the $6^{th}$ NFI data are fully collected, the uncertainty of estimated area should be improved.

• Asia Marketing Journal
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• 제14권4호
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• pp.57-75
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• 2013

It is a well-established theory that emotion is influential in cognitive processing. Extensive prior research on emotion has shown that emotional factors, such as affect, mood, and feeling, play as information indicating whether he or she has enough knowledge. Most of their findings focused on the effect of emotional valence (i.g., one's subjective positivity or negativity related with the emotion). Recently, several studies on emotion suggest that there is another dimension of emotion, which affects the type of cognitive processing. The studies argue that emotional certainty facilitates heuristic processing, whereas emotional uncertainty promotes systematic processing. Based on the findings, current study examines the effect of certainty on attitudes and recall. Specifically, the authors investigate the effect of certainty on how much effort individuals use to process advertising information and how certainty affects attitude formation toward the advertised product. The authors also focus on recall to clarify the working mechanism of certainty on attitudes, because recall performance reflects the depth of information processing. Based on previous findings, the authors hypothesize that uncertainty (vs. certainty) leads to more favorable attitudes as well as better recall, and conduct an experiment using a fictitious advertisement with 218 participants. The results confirm the predicted effects of certainty only on attitudes not recall. A possible explanation of this discrepancy between attitudes and recall lies in the measurement method, unaided recall. To rule out this possibility, the authors perform an additional analysis with the participants who recall any correct information of the target advertisement. The results show certainty has a negative effect on both attitudes and recall. A bootstrapping test reveals that recall mediates the effect of certainty on attitudes. This result confirms that certainty decreases elaboration, which in turn leads to less favorable attitudes relative to uncertainty. Additionally, our data shows the association among certainty, recall, and attitudes by showing the indirect effect of certainty on attitudes via recall. This research encourages practitioners in the field to emphasize that they should focus on target audiences' emotional certainty before they provide the persuasive message, by showing that uncertainty promotes effortful processing, which in turn leads to better memory and more favorable attitudes.

• 대한산업공학회지
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• 제26권1호
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• pp.36-47
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• 2000

DEA has been effectively applied to various areas which need the evaluation of relative efficiency. We propose a DEA model based on fuzzy LP in order to consider uncertain synergy effects due to M&A of existing organization. We apply the suggested approach to forecasting the efficiency of merged academic departments in a university in Korea. We expect that our approach can be utilized to effectively realign existing departments.