• 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.

• 한국동물학회지
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• 제15권1호
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• pp.15-21
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• 1972

두 케이스의 자궁암 조직을 배양하여 그들의 염색체를 구룹별로 분석한 결과는 아래와 같다. 1. 종족세포의 염색체수가 한 경우는 46이었고, 다른 한 환자에서는 60으로서 저3배성을 나타내었다. 2. 후자의 핵형을 구룹별로 분석한 결과, 구룹간의 염색체 분포는 non-random인 것으로 나타났다.

• 한국항행학회논문지
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• 제16권5호
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• pp.801-809
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• 2012

분산 제어 (DM; dispersion management)은 파장 분할 다중 (WDM; wavelength division multiplexed) 채널의 고품질 전송을 위해 광섬유의 그룹 속도 분산 (GVD; group velocity dispersion)과 비선형 효과의 상호 작용에 의해 왜곡되는 신호의 보상할 수 있는 대표적 기술이다. DM이 적용된 광전송 링크의 유연한 구성에 필요한 중계 구간 (fiber span)을 구성하는 단일 모드 광섬유 (SMF; single mode fiber)의 길이와 중계 구간 당 잉여 분산 (RDPS; residual dispersion per span)을 랜덤하게 분포시키는 구조와 인위적으로 분포시키는 구조에서의 최적 전체 잉여 분산 (NRD; net residual dispersion)의 최적치와 유효 입사 전력 범위를 도출하였다. 고려한 SMF의 길이와 RDPS 분포 패턴 모두 precompensation으로 NRD를 조절하는 경우에서는 +10 ps/nm, postcompensation으로 NRD를 조절하는 경우에서는 -10 ps/nm이 최적 NRD라는 것을 알 수 있었다. 그리고 NRD가 상기 값으로 설정된 경우 중계 구간이 증가할수록 SMF 길이를 감소시키고, RDPS를 증가시키는 인위적인 분포의 전송 링크에서의 시스템 성능이 가장 양호하여 균일한 분포의 링크에 비해 유효 입사 전력 범위가 2 dB 정도 신장되는 것을 확인하였다.

• Communications for Statistical Applications and Methods
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• 제26권6호
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• pp.583-589
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• 2019

Counterexamples of a skew-normal distribution are developed to improve our understanding of this distribution. Two examples on bivariate non-skew-normal distribution owning marginal skew-normal distributions are first provided. Sum of dependent skew-normal and normal variables does not follow a skew-normal distribution. Continuous bivariate density with discontinuous marginal density also exists in skew-normal distribution. An example presents that the range of possible correlations for bivariate skew-normal distribution is constrained in a relatively small set. For unified skew-normal variables, an example about converging in law are discussed. Convergence in distribution is involved in two separate examples for skew-normal variables. The point estimation problem, which is not a counterexample, is provided because of its importance in understanding the skew-normal distribution. These materials are useful for undergraduate and/or graduate teaching courses.

• 한국군사과학기술학회지
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• 제22권5호
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• pp.724-734
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• 2019

This study selected a representative small arm firing range and analyzed the distribution of heavy metal pollutants such as Pb, Cu, Zn, etc. For this the concentrations of heavy metals in soils, roots and leaves of plants, and water of the small arm firing range were measured. The concentrations of heavy metals in the effluent were also checked during precipitation. The concentration of lead in the samples collected from the top soil(0-5 cm) and sub soil(5-50 cm) near the target in the small arm firing range exceeded the concern level of the Soil Environment Conservation Act of Korea, but not in other soil samples. Plants that grow in soil heavily contaminated with lead showed a high lead concentration, especially in roots. However, the concentration of lead in effluent from the small arm firing range was less than 0.02 ppm. The concentration of copper and zinc in the small arm firing range did not surpass the concern level of the Soil Environment Conservation Act of Korea. Through this study more accurate information on the distribution of heavy metal pollution in the soil of the small arm firing range was obtained. Based on this research, we can conclude that some facility improvements can reduce the spreading of pollutants in the currently used small arm firing range and contribute to the design and operation of advanced small arm firing ranges.

• 한국해양공학회지
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• 제8권1호
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• pp.62-70
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• 1994

In order to estimate the detection range of a active SONAR system, the SONAR equation is commonly used. In this paper, an algorithm to calculate detection range in active SONAR system as function of SONAR depth and target depth is presented. For given SONAR parameters and environment, the transmission loss and background level are found, signal excess is computed. Using log-normal distribution, signal excess is converted to detection probability at each range. Then, the detection range is obtained by integrating the detection probability as function of range for each depth. The proposed algorithm have been applied to the case of omni-directional source with center frequency 30Hz for summer and winter sound profiles. It is found that the optimal search depth is the source depth since the detection range increase at source depth where the signal excess is maximized.

• 한국환경복원기술학회지
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• 제19권6호
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• pp.19-30
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• 2016

The projection of climate-related range shift is critical information for conservation planning of Korean fir (Abies koreana E. H. Wilson). We first modeled the distribution of Korean fir under current climate condition using five single-model species distribution models (SDMs) and the pre-evaluation weighted ensemble method and then predicted the distributions under future climate conditions projected with HadGEM2-AO under four $CO_2$ emission scenarios, the Representative Concentration Pathways (RCP) 2.6, 4.5, 6.0 and 8.5. We also investigated the predictive uncertainty stemming from five individual algorithms and four $CO_2$ emission scenarios for better interpretation of SDM projections. Five individual algorithms were Generalized linear model (GLM), Generalized additive model (GAM), Multivariate adaptive regression splines (MARS), Generalized boosted model (GBM) and Random forest (RF). The results showed high variations of model performances among individual SDMs and the wide range of diverging predictions of future distributions of Korean fir in response to RCPs. The ensemble model presented the highest predictive accuracy (TSS = 0.97, AUC = 0.99) and predicted that the climate habitat suitability of Korean fir would increase under climate changes. Accordingly, the fir distribution could expand under future climate conditions. Increasing precipitation may account for increases in the distribution of Korean fir. Increasing precipitation compensates the negative effects of increasing temperature. However, the future distribution of Korean fir is also affected by other ecological processes, such as interactions with co-existing species, adaptation and dispersal limitation, and other environmental factors, such as extreme weather events and land-use changes. Therefore, we need further ecological research and to develop mechanistic and process-based distribution models for improving the predictive accuracy.

• 한국대기환경학회지
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• 제2권2호
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• pp.9-18
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• 1986

For identification and apportionment of sources emitting particulate matters in environment, the multi-elemental characterization of size-density fractionated particulate matters was carried out. Eight types of samples were tested; soil, flyash released from burning of bunker-Coil, diesel oil, coal, and soft coal, urban road-way dust, urban dust fall, and airborne particulate matter. The fractions of particulate matters obtained by heavy liquid separation methos with a series of dichloromethane-bromoform were then analyzed using atomic absorption spectrophotometry for Ni, Cr, Cu, An, Fe, Al, and Mg. Each sample showed a different concentration profile as a function of density, and a number of useful conclusions concerning characterization of elemental distribution were obtained. From the density distributions of elements in soil, the maximum value was found for all elements in the density range of 2.2 $\sim 2.9g.cm^{-3}$, including the density of $SiO_2$. However, the distribution of metallic compounds with the density lower than $2.2g.cm^{-3}$ was prevalent in urban roadway dust, urban dust fall, and airborne particulate matter. And the density distribution curves of these urban dusts also have the higher distribution at the density of 2.2 - 2.9g.cm^{-3}$, including the density of wind-blown silica. This tendency generally was prevalent in the natural source elements, such as Al, Fe, Mn, and Mg. The maximum values were found in the density ranges of 1.3 $\sim 2.2g.cm^{-3}$ from the density distribution of elements in oil fired flyash. These distributions of anthropogenic source elements, such as Zn, Ni, Cu, and Cr were higher predominately than those of natural source elements. And the higher distribution was found in the density range of $2.2 \sim 2.9g.cm^{-3}$ from the density distribution of elements in coal and soft-coal fired flyash. These distributions showed similar patterns to soil. But anthropogenic source elements somewhat predominated at the density ranges of $1.3 \sim 2.2g.cm{-3} and 2.9g.cm^{-3}$ to soil. Therefore the higher distribution of anthropogenic source elements in the density ranges of $1.3 \sim 2.2g.cm^{-3} and 2.9g.cm^{-3}$ was considered as anthropogenic origin.

• 한국수학교육학회지시리즈A:수학교육
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• 제58권4호
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• pp.531-543
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• 2019

본 연구는 2009개정 교육과정과 2015개정 교육과정을 반영한 교과서에서 연속확률분포를 정의하고 도입하는 방법에 대해 비교 분석하였다. 2015개정 교육과정을 반영한 확률과 통계 교과서는 연속확률변수를 가부번집합인 확률변수로 정의하기보다는 특정 범위의 모든 실숫값을 가지는 확률변수로 정의하였다. 또한 연속확률분포를 도입함에 있어 균등분포를 이용한 방법과 상대도수밀도를 이용한 방법을 사용하였다.

• 대한수학회보
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• 제34권2호
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• pp.295-303
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• 1997

Let ${X_k : k = 1, 2, \cdots}$ be a sequence of independent, identically distributed integer-valued random variables with common distribution function F.