• 한국지구과학회지
• /
• 제26권2호
• /
• pp.114-128
• /
• 2005

Fuzzy information representation of multi-source spatial data is applied to landslide hazard mapping. Information representation based on frequency ratio and non-parametric density estimation is used to construct fuzzy membership functions. Of particular interest is the representation of continuous data for preventing loss of information. The non-parametric density estimation method applied here is a Parzen window estimation that can directly use continuous data without any categorization procedure. The effect of the new continuous data representation method on the final integrated result is evaluated by a validation procedure. To illustrate the proposed scheme, a case study from Jangheung, Korea for landslide hazard mapping is presented. Analysis of the results indicates that the proposed methodology considerably improves prediction capabilities, as compared with the case in traditional continuous data representation.

• Journal of the Korean Data and Information Science Society
• /
• 제28권2호
• /
• pp.443-449
• /
• 2017

Estimation of population proportion like the distribution rate of LED TV and the prevalence of a disease are often estimated based on survey sample data. Population proportion is generally considered as a special form of population mean. In complex sampling like stratified multistage sampling with unequal probability sampling, the denominator of mean may be random variable and it is estimated like ratio estimator. In this research, we examined the estimation of distribution rate based on stratified multistage sampling, and determined some numerical outcomes using stratified random sample data with about 25% of missing observations. In the data used for this research, the survey weight was determined by deterministic way. So, the weights are not random variable, and the population distribution rate and its variance estimator can be estimated like population mean estimation. When the weights are not random variable, if one estimates the variance of proportion estimator using ratio method, then the variances may be inflated. Therefore, in estimating variance for population proportion, we need to examine the structure of data and survey design before making any decision for estimation methods.

• 벤처창업연구
• /
• 제3권1호
• /
• pp.57-72
• /
• 2008

본 논문에서는 그동안 부분적으로 진행된 발달장애 진단 평가에 관련된 전산처리를 멀티미디어 기법을 응용하여 발달장애 진단 평가분야에 새로운 방법을 제시한다. 발달장애 진단 평가를 위한 멀티미디어 정보는 여러 가지 속성을 지니고 있기 때문에 모든 발달장애 진단 평가 정보에 대한 기술을 사람이 수행해야 할 때는 엄청난 작업량이 수반될 뿐 아니라 동일한 데이터에 대한 기술이 주관에 따라 달라질 수도 있다는 것을 알게 되였다. 특히 발달장애 시스템 구현은 현재의 컴퓨팅 환경에서의 동영상 데이터 처리에 대한 비중의 증가, 텍스트 위주의 데이터에서 시각적인 동영상으로의 데이터 활용의 전이 등 발달장애 데이터가 멀티미디어 환경에 적합한 데이터로의 전이가 필수적이며 사용자 역시 빠른 이해를 위해 시각적 데이터를 선호하기 때문에 본 논문에서는 GUI(Graphics User Interface) 기법을 도입하여 검사 중에 텍스트 명령어는 거의 사용하지 않고도 발달장애 진단 평가를 수행할 수 있게 했다. 특히 발달장애 진단 평가에서 필요한 각종 데이터는 그 속성이 영상, 이미지, 논리연산의 필요성 및 각종 연산이 요구된다. 그래서 본 논문에서는 문제점을 해결하기 위해 편집대상 데이터(Content)에 의해 관련 정보를 검색하는 내용 기반(Content-based)의 검색 기술에 대한 연구를 적용했다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권11호
• /
• pp.5365-5380
• /
• 2016

Estimation of signal-to-noise ratio (SNR) is an important problem in wireless communication systems. It has been studied for various constellation types and channels using different estimation techniques. Maximum likelihood estimation is a technique which provides efficient and in most cases unbiased estimators. In this paper, we have applied maximum likelihood estimation for systems employing square or cross QAM signals which are undergoing slow flat Rayleigh fading. The problem has been considered under various scenarios like data-aided (DA), non-data-aided (NDA) and partially data-aided (PDA) and the performance of each type of estimator has been evaluated and compared. It has been observed that the performance of DA estimator is best due to usage of pilot symbols, with the drawback of greater bandwidth consumption. However, this can be catered for by using partially data-aided estimators whose performance is better than NDA systems with some extra bandwidth requirement.

• Communications for Statistical Applications and Methods
• /
• 제7권3호
• /
• pp.811-816
• /
• 2000

The purpose of this paper is to study of data-driven smoothing goodness of it test, when the hypothesis is complete. The smoothing goodness of fit test statistic by nonparametric function estimation techniques is proposed in this paper. The results of simulation studies for he powers of show that the proposed test statistic compared well to other.

• Journal of the Korean Data and Information Science Society
• /
• 제16권2호
• /
• pp.411-418
• /
• 2005

We review support vector and wavelet density estimation. The relationship between support vector and wavelet density estimation in reproducing kernel Hilbert space (RKHS) is investigated in order to use wavelets as a variety of support vector kernels in support vector density estimation.

• 한국철도학회논문집
• /
• 제20권5호
• /
• pp.692-702
• /
• 2017

최근 데이터 중심적 교통정책수립 필요성 인식에 따라 교통카드데이터 활용에 관심이 고조되고 있다. 하지만 수도권 외의 많은 지역의 데이터에 하차 정보가 없어 활용에 제약이 있다. 이 논문은 승차 정보만 포함된 교통카드데이터에서 하차 정류장을 추정하는 방법론을 제시하였다. 검증은 서울시와 광주시의 데이터를 활용하였다. 추정 성공률은 서울시, 광주시 각각 78.2%, 81.6%로 나타났다. 정확도는 각각 54.2%, 33.4%로 나타났는데, 2개 정류장 오차까지 허용하는 경우 정확도가 서울시 93.6%, 광주시 94.0%로 크게 높아진다. 또한 광주시와 서울시가 오차 양상이 다름을 밝혔다. 통행사슬 방법의 핵심 매개변수인 허용 도보거리 조정에 따른 추정 성공률 및 정확도의 변화도 다루었다. 허용 도보거리가 증가됨에 따라 추정 성공률은 높아지는 반면 추정 정확도는 낮아지는 것을 확인하였으며, 500m를 전후하여 추정 결과의 변화 양상이 있음을 발견하였다.

• 한국지진공학회:학술대회논문집
• /
• 한국지진공학회 2001년도 춘계학술대회 논문집
• /
• pp.74-80
• /
• 2001

The estimation of recurrence interval for fault activity and earthquake is an important input parameter for seismic hazard assessment. In this study, the methods of recurrences interval estimation were reviewed and tentative calculation was performed for age dating data which have uncertainty. Age dating data come from previous studies of Ulsan fault system which is a well developed lineament in the southeastern part of korean Peninsula. Age dating for fault gouges, parent rocks, Quaternary sediments and veins were carried out by several researchers through various methods. Recurrence interval for fault activity was estimated on the basis of the age dating data of minor fault gouge and sediments during past 3Ma. The estimated recurrence interval was about 430-500 ka. Exact estimation of recurrence interval for fault activity need to compile more geological data and fault characteristics such as fault length, amount of displacement, slip rate and accurate fault movement age. In the future, the methods and results of fault recurrence interval estimation should be considered for establishing the criteria for domestic active fault definition.

• Transactions on Control, Automation and Systems Engineering
• /
• 제1권1호
• /
• pp.75-86
• /
• 1999

An air-data estimator for generic air-breathing hypersonic vehicles (AHSVs) is developed and demonstrated with an example vehicle configuration. The AHSV air-data estimation strategy emphasized improvement of the angle of attack estimate accuracy to a degree necessitated by the stringent operational requirements of the air-breathing propulsion. the resulting estimation problem involves highly nonlinear diffusion process (propagation); consequently, significant distortion of a posteriori conditional density is suspected. A simulation based statistical analysis tool is developed to characterize the nonlinear diffusion process. The statistical analysis results indicate that the diffusion process preserves the symmetry and unimodality of initial probability density shape state variables, and provide the basis for applicability of an Extended Kalman Filter (EKF). An EKF is designed for the AHSV air-data system and the air data estimation capabilities are demonstrated.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.917-919
• /
• 2003

This paper demonstrates that RADARSAT ScanSAR data can be an important data source of radar remote sensing for monitoring crop systems and estimation of rice yield for large areas in tropic and sub-tropical regions. Experiments were carried out to show the effectiveness of RADARSAT ScanSAR data for rice yield estimation in whole province of Guangdong, South China. A methodology was developed to deal with a series of issues in extracting rice information from the ScanSAR data, such as topographic influences, levels of agro-management, irregular distribution of paddy fields and different rice cropping systems. A model was provided for rice yield estimation based on the relationship between the backscatter coefficient of multi-temporal SAR data and the biomass of rice.