• Communications for Statistical Applications and Methods
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• 제20권4호
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• pp.321-327
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• 2013

Bayesian and empirical Bayesian methods have become quite popular in the theory and practice of statistics. However, the objective is to often produce an ensemble of parameter estimates as well as to produce the histogram of the estimates. For example, in insurance pricing, the accurate point estimates of risk for each group is necessary and also proper dispersion estimation should be considered. Well-known Bayes estimates (which is the posterior means under quadratic loss) are underdispersed as an estimate of the histogram of parameters. The adjustment of Bayes estimates to correct this problem is known as constrained Bayes estimators, which are matching the first two empirical moments. In this paper, we propose a way to apply the constrained Bayes estimators in insurance pricing, which is required to estimate accurately both location and dispersion. Also, the benefit of the constrained Bayes estimates will be discussed by analyzing real insurance accident data.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2008년도 추계학술발표대회
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• pp.1222-1223
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• 2008

본 논문에서는 1분에 최대 200 개의 위치보고를 처리하여야 하는 제주 택시 텔레매틱스 시스템에서 보다 효율적인 트래킹과 택시 배차를 위해 맵 매칭에 의해 차량이 위치한 도로를 검색하는 모듈을 설계하고 구현한다. 구현된 모듈은 위치기반 서비스에 있어서 저비용 효율적으로 맵 매칭을 구현하기 위해 쉐이프 파일을 직접 순차적으로 처리하고 보고지점과 세그먼트들로 이루어진 삼각형의 면적을 기반으로 매칭 링크를 검색한다. 이 기능은 차량의 진행방향을 판단하거나 도로 내에서의 위치 비율을 계산하는데 용이하며 다양한 부가 정보를 생성할 수 있다. 구현된 시스템에서 실제 히스토리 데이터에 대해 맵 매칭을 수행한 결과 95% 이상 해당 링크를 검색하였다.

• 한국컴퓨터정보학회논문지
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• 제19권11호
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• pp.43-52
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• 2014

본 논문에서는 적외선 영상에서 영상 변위를 이용하여 기동 표적 영역을 탐지하고, SURF(Speeded Up Robust Features) 특징점에 대한 BAS(Beam Angle Statistics)를 이용하여 분류하는 시스템에 대하여 설명한다. 영상 기반 기술 분야에서 대표적인 대응점 정합 알고리즘인 SURF 기법은 SIFT(Scale Invariant Feature Transform) 기법에 비해 정합 속도가 매우 빠르고 비슷한 정합 성능을 보이기 때문에 널리 사용되고 있다. SURF를 이용한 대부분의 객체 인식의 경우 특징점 추출과 정합의 과정을 수행하지만, 제안하는 기법은 표적의 기동 특성을 반영하여 영상의 변위 추정을 통하여 표적의 영역을 탐지하고 SURF 특징점 들의 기하구조를 판단함으로써 표적 분류를 수행한다. 제안하는 기법은 무인 표적 탐지/인지 시스템의 초기모델 구축을 위하여 연구가 진행되었으며, 모의 표적을 이용한 가상 영상과 적외선 실 영상을 이용하여 실험한 결과 약 73~85%의 분류 성능을 확인하였다.

• Asian Journal for Public Opinion Research
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• 제10권3호
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• pp.200-229
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• 2022

The purpose of this study is to analyze the effects of youth job policy measures, set forth in Korea's 2016-2020 Third Basic Plan for Low Fertility and Aging Society (December 2015), on marriage and fertility among young people. Based on the results, we provide theoretical explanations for the findings and suggest policy alternatives to overcome the low fertility phenomenon in Korea. Previous studies have shown that employment is an important factor for marriage among youth, and a job policy could increase marriage and fertility rates. To test this assumption, we performed an exact matching between Statistics Korea's Employee-Enterprise Linkage DB and the Newlyweds DB from 2011 to 2019, in order to identify all young people aged 15-34. Then, linear spline regression analysis was used to examine the impact of the youth job policy on marriage and fertility. Comparing the period before the implementation of the employment policy (2011-2015) and after (2016-2019), the fertility rate increased as the number of young people looking for work increased. In addition, it was found that these impacts were greater after the implementation of the measures (2016-2019) than before (2011-2015). It is interesting to note that job growth among young people did not lead to an increase in marriage. However, the number of births significantly increased when young people who occupy jobs got married, which seems to be related to the delay in marriage among young people who are employed. Survey results about the intentions to marry and views on fertility are utilized for the explanation of the study results.

• Communications for Statistical Applications and Methods
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• 제18권6호
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• pp.675-685
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• 2011

본 연구는 구직자의 구직희망조건과 구인기업의 구인조건을 동시에 고려하여 특정 구직자가 특정 기업에 잡매칭될 가능성을 판단할 수 있는 잡매칭 함수를 제안하였다. 그리고 사회연결망분석(social network analysis)을 이용하여 구직자와 구인기업간의 상호작용의 가능성을의미하는 연결정도 중심성을 분석하였다. 분석결과는 다음과 같다. 첫째, 연결정도는 일부의 구직자 또는 구인기업에게 심하게 편중되어 있음을 알 수 있다. 그리고 전혀 매칭되지 않는 구직자와 구인기업의 수도 다수인 것으로 나타났다. 둘째, 의사결정나무 분석 결과에 의하면, 구직자 특성들 중 연결정도 중심성에 가장 많은 영향을 미친 특성은 성별이었고, 그 다음으로 연령, 학력 등의 순으로 나타났다. 그리고 구인기업특성들 중 연결정도 중심성에 가장 많은 영향을 미친 특성은 제시임금이었고, 그 다음으로 업종, 기업규모의 순으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권2호
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• pp.583-599
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• 2015

We apply the Bayesian matching pursuit (BMP) algorithm to the estimation of time-frequency selective channels in orthogonal frequency division multiplexing (OFDM) systems. By exploiting prior statistics and sparse characteristics of propagation channels, the Bayesian method provides a more accurate and efficient detection of the channel status information (CSI) than do conventional sparse channel estimation methods that are based on compressive sensing (CS) technologies. Using a reasonable approximation of the system model and a skillfully designed pilot arrangement, the proposed estimation scheme is able to address the Doppler-induced inter-carrier interference (ICI) with a relatively low complexity. Moreover, to further reduce the computational cost of the channel estimation, we make some modifications to the BMP algorithm. The modified algorithm can make good use of the group-sparse structure of doubly selective channels and thus reconstruct the CSI more efficiently than does the original BMP algorithm, which treats the sparse signals in the conventional manner and ignores the specific structure of their sparsity patterns. Numerical results demonstrate that the proposed Bayesian estimation has a good performance over rapidly time-varying channels.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권3호
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• pp.51-64
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• 2015

In the present study, we develop two history matching techniques based on Markov chain Monte Carlo method where radial basis function and Gaussian distribution generated by unconditional geostatistical simulation are employed as the random walk transition kernels. The Bayesian inverse methods for aquifer characterization as the developed models can be effectively applied to the condition even when the targeted information such as hydraulic conductivity is absent and there are transient hydraulic head records due to imposed stress at observation wells. The model which uses unconditional simulation as random walk transition kernel has advantage in that spatial statistics can be directly associated with the predictions. The model using radial basis function network shares the same advantages as the model with unconditional simulation, yet the radial basis function network based the model does not require external geostatistical techniques. Also, by employing radial basis function as transition kernel, multi-scale nested structures can be rigorously addressed. In the validations of the developed models, the overall predictabilities of both models are sound by showing high correlation coefficient between the reference and the predicted. In terms of the model performance, the model with radial basis function network has higher error reduction rate and computational efficiency than with unconditional geostatistical simulation.

• 품질경영학회지
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• 제31권4호
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• pp.219-225
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• 2003

Two­dimensional warranty data can be modelled using two different approaches： two­dimensional point process and one­dimensional point process with usage as a function of age. The first approach has three different models. First of all, bivariate model is appealing but is not appropriate for explaining warranty claims. Next, the rest of the two models (marked point process, and counting and matching on both directions independently) are more appropriate for explaining warranty claims. However, the second one (counting and matching on both directions independently) assumes that the two variables (variables representing the two­dimensions) are independent. Last of all, one­dimensional point process with usage as a function of age is also promising to explain the two­dimensional warranty claims. But the models or variations of them need more investigation to be applicable to real warranty claim data.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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• pp.304-309
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• 1999

In this paper, we presents a new disparity map refinement algorithm using statistical characteristics of disparity map and edge information. The proposed algorithm generate a refined disparity map using disparity maps which are obtained from area and feature-based Stereo Matching by selecting a disparity value of edge point based on the statistics of both disparity maps. Experimental results on aerial stereo image show the better results than conventional fusion algorithms in the disparity error. This algorithm can be applied to the reconstruction of building image from the high resolution remote sensing data.

• 응용통계연구
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• 제15권2호
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• pp.405-414
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• 2002

반복이 같은 이원배치 혼합효과 분산분석모형에서 무정보 사전분포를 이용하여 오차분산을 추정하는 문제를 생각하고자 한다. 먼저 무정보 사전분포로 제프리스사전분포, 준거 사전분포 그리고 확률일치 사전분포를 유도하고 이들 각각의 사전분포들에 대하여 주변사후분포를 제시하였다. 끝으로 실제 자료를 근거로 오차분산의 주변사후밀도함수에 대한 그래프와 오차분산에 대한 신용구간들을 구하고 이 구간들을 비교한다.