• Geophysics and Geophysical Exploration
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• v.12 no.1
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• pp.8-16
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• 2009

The holistic inversion approach for frequency domain airborne electromagnetic data has previously been employed to simultaneously calibrate, process and invert raw frequency-domain data where prior information was available. Analternative formulation has been developed, which is suitable in the case where explicit prior information is not available. It incorporates: a multi-layer vertically-smooth conductivity model; a simplified bias parameterisation; horizontal smoothing with respect to elevation; and cluster computer parallelisation. Without using any prior data, an inversion of 8.0 million data for 3.4 million parameters yields results that are consistent with independently derived calibration parameters, downhole logs and groundwater elevation data. We conclude that the success of the holistic inversion method is not dependent on a sophisticated conceptual model or the direct inclusion of survey-area specific prior information. In addition, acquisition costs could potentially be reduced by employing the holistic approach which largely eliminates the need for high altitude zero-level measurements.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.230-232
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• 2007

본 논문은 인간의 언어정보처리과정 중 초기 어휘획득(lexical acquisition) 과정을 한국어에 적용시켜 Full-List 모형과 Decomposition 모형의 하이브리드한 형태의 계산주의적 (computational) 어휘정보처리 모델을 구현하고 실험하였다. 실험결과 학습을 통한 언어적 입력의 인간의 어휘획득 과정을 모사(simulate) 할 수 있었고, 특정 문법범주 습득 순서에 대한 이론적 근간을 제시할 수 있었다. 또한 본 연구의 모델에서 자동으로 생성된 Full-List 사전과 Decomposition 사전을 통해 인간의 대뇌 심성표상(mental representation) 형태를 유추할 수 있는 증거를 보였다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2014.01a
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• pp.145-147
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• 2014

공동주의는 사회적 개체간의 지각적 경험을 공유하는 상호작용과정으로, 최근 인간-로봇 상호작용연구와 관련해서 로봇 공학자의 관심이 커지고 있다. 발달심리학에 기초한 기존의 developmental robotics의 접근과는 달리, 본 연구에서는 사전단서 패러다임을 이용해서 목표물, 단서, 주의반응 간의 삼자관계를 수학적으로 개념화하였다. 간단한 목표물 탐사과제를 통해서 계산모형의 수행을 검증하였다. 연구결과에서는 컴퓨터 시스템의 시각적 주의 모형이 사용자가 지시하는 단서(손가락 지시)의해 목표물(이온음료)을 주의를 할당하는 것을 보였다. 본 연구는 심리학에서 연구된 사전단서 패러다임을 인간-로봇 상호작용에 적용될 수 있음을 보여준다.

• Proceedings of the Korea Water Resources Association Conference
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• 2010.05a
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• pp.784-788
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• 2010

본 연구는 자연재해대책법에 의해 개발사업으로 인한 재해유발요인을 예측 분석하고 이에 대한 대책을 강구하기 위해 수행되고 있는 사전재해영향평가에서 토양유실도 작성을 위한 HyGIS와 연계한 토양유실량 분석 모형을 개발하는 것을 목적으로 하고 있다. HyGIS(Hydro Geographic Information System)는 GIS를 수자원의 다양한 분야에 손쉽게 적용하기 위해서 컴포넌트 형태로 개발된 시스템이다. HyGIS에서는 DEM을 이용하여 유역 및 하천망의 추출과 지형분석이 가능하며, 하천 네트워크를 기반으로 유역의 다양한 정보를 운용할 수 있다. 또한 HyGIS는 데이터베이스를 기반으로 운영되며, GIS를 이용한 수자원 분야의 응용프로그램 개발 시 기반 시스템으로 활용될 수 있다. 본 연구에서 개발한 HyGIS와 연계한 토양유실 분석 모형은 HyGIS의 데이터베이스를 공동으로 이용할 수 있도록 개발하였다. 개발 툴은 GEOMania GMMap2009의 Add-on 형태로 개발하였고, OECD에서 제안한 토양유실 위험 등급도도 작성할 수 있도록 개발하였다.

• Journal of Korea Water Resources Association
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• v.49 no.6
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• pp.481-493
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• 2016

The statistical analysis to the torrential rainfall data that is defined as a rainfall amount more than 80 mm/day is performed with Daegu and Busan rainfall data which is collected during 384 months. The number of occurrence of the torrential rainfall events can be simulated usually using Poisson distribution. However, the Poisson distribution can be frequently failed to simulate the statistical characteristics of the observed value when the observed data is zero-inflated. Therefore, in this study, Generalized Poisson distribution (GPD), Zero-Inflated Poisson distribution (ZIP), Zero-Inflated Generalized Poisson distribution (ZIGP), and Bayesian ZIGP model were used to resolve the zero-inflated problem in the torrential rainfall data. Especially, in Bayesian ZIGP model, a informative prior distribution was used to increase the accuracy of that model. Finally, it was suggested that POI and GPD model should be discouraged to fit the frequency of the torrential rainfall data. Also, Bayesian ZIGP model using informative prior provided the most accurate results. Additionally, it was recommended that ZIP model could be alternative choice on the practical aspect since the Bayesian approach of this study was considerably complex.

• Journal of the Korean Society for information Management
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• v.19 no.1
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• pp.135-161
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• 2002

This study presents a multilingual integrated ontological approach that enables linking classification systems. thesauri. and terminology databases in science and technology for more effective indexing and information retrieval online. In this integrated system, we designed a thesaurus model with concept as a unit and designated essential data elements for a terminology database on the basis of ISO 12620 standard. The classification system for science and technology adopted in this study provides subject access channels from other existing classification systems through its mapping table. A prototype system was implemented with the field of nuclear energy as an application area.

• Journal of the Korean Data and Information Science Society
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• v.22 no.3
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• pp.459-466
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• 2011

This article addresses robust Bayesian modeling for meta analysis which derives general conclusion by combining independently performed individual studies. Specifically, we propose hierarchical Bayesian models with unknown variances for meta analysis under priors which are scale mixtures of normal, and thus have tail heavier than that of the normal. For the numerical analysis, we use the Gibbs sampler for calculating Bayesian estimators and illustrate the proposed methods using actual data.

• The Transactions of the Korea Information Processing Society
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• v.1 no.1
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• pp.14-22
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• 1994

This paper proposes two Bayes estimators and their evaluation algorithms of the software reliability at the end testing stage in the Smith's Bayesian software reliability growth model under the data prior distribution BE(a, b), which is more general than uniform distribution, as a class of prior information. We consider both a squared-error loss function and the Harris loss function in the Bayesian estimation procedures. We also compare the MSE performances of the Bayes estimators and their algorithms of software reliability using computer simulations. And we conclude that the Bayes estimator of software reliability under the Harris loss function is more efficient than other estimators in terms of the MSE performances as a is larger and b is smaller, and that the Bayes estimators using the beta prior distribution as a conjugate prior is better than the Bayes estimators under the uniform prior distribution as a noninformative prior when a＞b.

• Journal of KIISE:Software and Applications
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• v.32 no.4
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• pp.327-334
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• 2005

Recently, ICT has emerged as an indispensable tool for teaching a variety of subjects in education systems. In this paper, we examine the effect of the instructional models for ICT on the practical ability in the application of information with relation to the levels of self-regulated learning strategies. Students were divided into 3 groups, according to the instructional model for ICT which were problem search learning, problem solution learning, and discussion learning. As an experimental tools, we did pretest using self-regulated learning strategies measurement questionnaire and did pretest and posttest using practical ability in the application of information measurement questionnaire. The results show that higher level of self-regulated teaming strategies group has high practical ability in the application of information than lower level group. Other interesting results are also provided.

• Journal of the Korean Society for information Management
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• v.15 no.1
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• pp.129-148
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• 1998

The objective of this study is to develop a useful relevance feedback retrieval technique that can be applied to the current Boolean retrieval system. A feedback retrieval technique based on user model is recommended here to achieve this objective. To prove the usefulness of this feedback retrieval technique, two enhanced Boolean retrieval models including DNF model and P-norm model were evaluated first through retrieval effectiveness experiments. After selecting DNF model as the retrieval model, two feedback retrieval experiments were performed using initial and extended user models. It is proved that the feedback retrieval based on user model can greatly enhance the effectiveness of a Boolean retrieval system with a small modification.