• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(5)
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• pp.95-98
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• 2000

Evaluation of the acoustic nasal geometry is obtained by estimating impulse response due to the nasal geometry. Conventionally, the Wiener filtering method proposed by Hunt has been used for estimating impulse response. In this paper, we proposed the Weiner filtering method using noise-to-signal power ratio for estimating impulse response. In result, the proposed method in this paper is effective than the conventional method.

• Journal of the Korean Data and Information Science Society
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• 제10권1호
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• pp.207-214
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• 1999

Optimal estimating functions for a class of autoregressive models with GARCH(1,1) error are discussed. The asymptotic properties of the estimator as the solution of the optimal estimating equation are investigated for the models. We have also some simulation results which suggest that the proposed optimal estimators have smaller sample variances than those of the Conditional least-squares estimators under the heavy-tailed error distributions.

• Journal of the Korean Data and Information Science Society
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• 제16권1호
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• pp.33-40
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• 2005

The estimating function method was proposed by Godambe(1985) for parameter estimation under unknown distributions for errors in the models. Threshold Autoregressive Heteroscedastic (Threshold-ARCH) models have been developed by Zakoian(1994) and Li and Li(1996) for explaining the asymmetric properties in the financial time series data. In this paper, we apply the estimating function method to the Threshold-ARCH model and show that the proposed estimators perform better than the MLE under the heavy-tailed distributions.

• 한국건설관리학회논문집
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• 제8권4호
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• pp.155-166
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• 2007

본 연구는 건축공사 프로젝트의 기본 설계 단계에서의 개산견적 개념모델을 제안하고, 제안된 개산견적 개념을 적용하여 실제 주상복합 건물 프로젝트의 실적자료의 분석을 바탕으로 한 프로토타입 개발을 목적으로 한다. 국내의 건설산업은 급격한 시장 변화와 경쟁 심화의 과정을 겪고 있다. 특히 프로젝트의 조달 방식의 변화와 함께 입찰과 관련한 정보가 부족한 사업초기, 기본설계 단계에서 중요한 의사 결정이 이루어지며, 이러한 의사 결정의 기준이 되는 개산 견적의 중요성이 더욱 증가 되고 있다. 따라서 본 연구에서는 기존의 개산견적 방법을 분석하고 그것을 보완할 수 있는 공사 수량 변화 분석에 기반 한 개산견적 방법을 제안하고 프로토타입을 구축하였다. 또한, 이 연구에서는 기존의 공종별 공사비 분류체계에 빌딩구성요소(BE)별 및 층별 수량 분류를 추가하고 있다. 이러한 개념을 바탕으로 제안 모델을 Q-BASE (Quantity Based Active Schematic Estimating) 모델로 정의하였다.

• 한국수학교육학회지시리즈A:수학교육
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• 제48권3호
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• pp.329-352
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• 2009

The purpose of this study was to investigate the effects of small group cooperative communicative activities on the strategies for estimating measurement. To do this, two research questions were set as follow: First, are there any differences between strategies employed by students in the experimental group and the control group before and after the estimating measurement activities? Second, are there any differences between strategies employed by students in different ability levels(upper, middle, lower) of pre-estimating measurement test in the experimental group? The research results were drawn from the investigation as below: First, the strategical change of before and after the estimating measurement tasks in the experimental group was quite noticeable. Unlike the small strategical change in the control group, small group cooperative communicative learning resulted in a decrease of simple memorization and guessing strategies and an increase of refined strategies such as the standard strategy, clustering, unit load and so on. Second, mathematical communicative activities in a small group cooperative learning showed that the students in the upper level of pre-estimating measurement test used more refined strategies and the students in the lower level used simple memorization and guessing strategy more frequently. And through interaction in small group, students could have chances to recognize error of strategies and to modify and learn strategies. In conclusion, small group cooperative activities allowed students to have chances to communicate mathematically and it is a efficient way of helping students learn estimating measurement strategies.

• Communications for Statistical Applications and Methods
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• 제7권1호
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• pp.269-276
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• 2000

there are several methods available for estimating parameters in overdispersed binary response data with the litter effect. Simulations are performed to compare methods for estimating an overall mean and an overdispersion parameter using moments a maximum likelihood under a beta-binomial distribution a maximum quasi-likelihood and a maximum extended quasi-likelihood.

• Journal of the Korean Data and Information Science Society
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• 제14권3호
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• pp.687-696
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• 2003

This article presents a new family of the estimating functions related with minimum distance estimations, and discusses its relationship to the family of the minimum density power divergence estimating equations. Two representative minimum distance estimations; the minimum $L_2$ distance estimation and the minimum Hellinger distance estimation are studied in the light of the theory of estimating equations. Despite of the desirable properties of minimum distance estimations, they are not widely used by general researchers, because theories related with them are complex and are hard to be computationally implemented in real problems. Hopefully, this article would be a help for understanding the minimum distance estimations better.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.685-691
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• 2009

Recently, public office building projects are being recognized by many construction engineers and researchers, as the critical projects in the construction industry. The project budgets have sometimes exceeded due to the lack of core knowledge, experiences, skills and experts concerned in cost planning and estimating in the pre-construction stage. It has been highlighted that planning and estimating effectively the cost of public office building projects as critical in the design stage. Within this context, some cost data books and systems, such as RSMeans cost data systems and Spon's price book, have been systematically developed and used by many construction cost managers and organizations in order to effectively estimate and use their project budgets. As a result of this research, a cost estimating model for finishes has been developed, considering the cost data used in public office building projects.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.604-605
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• 2015

To secure quality of dam construction needs appropriate construction duration. Tight construction schedule may have negative influence on infrastructure quality, work safety and maintenance cost. It is necessary to reflect proper construction duration in the planning phase. There have been standards for estimating construction duration of building and industrial complex development but dam construction have not. In order to estimate construction duration of CFRD, feasible study reports and design reports were analyzed to acquire available information. After that, considering on construction duration methods such as comparison with similar cases, approximate estimating formula, approximate quantity assumption were adapted to Critical Path items. Hence, this study present framework for construction duration estimating of CFRD in the planning phase. This framework can be applied other types of dam along the same line.

• 한국과학교육학회지
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• 제23권3호
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• pp.229-238
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• 2003

일상적인 경험을 바탕으로 중학생들이 도구를 사용하지 않고 물리량의 치수를 어림하는 능력을 조사하였다. 이를 위하여 연구자들은 기본량에 해당하는 길이와 질량, 유도량에 해당하는 속력, 부피, 밀도에 대한 차수 어림 능력을 묻는 선택형 문항을 개발하였고, 서울지역 중학교 1학년과 3학년 학생 448명이 조사에 참가하였다. 전체적으로 반 이상의 학생들이 물리량의 치수를 참값과 다르게 어림하고 있었는데, 차원이 복잡한 유도량이거나 크기가 작을수록 차수 어림 능력이 낮아졌다. 학년에 따른 차이는 크지 않았으나 성별에 따라서 차수 어림 능력에 차이가 있었고 상대적으로 남학생이 길이 어림을 잘 하였다. 결론적으로 반수 이상의 학생들이 물리량이 차수를 제대로 어림하지 못한다는 점은 물리량과 단위에 대한 정성적인 이해가 부족함을 나타내며, 기능적인 측면을 강조하는 측정 교육이 가지는 한계점을 보여주었다. 따라서 실제 측정을 통하여 구한 물리량의 정성적인 의미를 이해할 수 있도록 하기 위하여 어림 교육이 필요함을 시사하고 있다.