• 대한음성학회지:말소리
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• 제50호
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• pp.123-137
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• 2004

In this paper, we consider the implementation of connected digit recognition system using tree structured lexicon model. To implement efficiently the fixed or variable length digit recognition system, finite state network (FSN) is required. We merge the word network algorithm that implements the FSN with lexical tree search algorithm that is used for general speech recognition system for fast search and large vocabulary systems. To find the efficient modeling of digit recognition system, we investigate some performance changes when the lexical tree search is applied.

• 한국산업정보학회논문지
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• 제24권2호
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• pp.1-14
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• 2019

웹, XML, 오피스 어플리케이션에 사용되는 대부분의 문서들은 트리 구조로 구성되어 있으며 특히 다중 사용자 환경에서의 트리 구조의 문서의 차이 발견, 합병, 버전 제어 등의 연구가 활발하다. 그러나 이들의 기초가 되는 편집스크립트에 대한 연구는 초보적인 상태에 있다. 본 논문에서는 편집연산들의 실행 시 트리구조의 문서의 변화를 이해하기 위한 문서 모델을 제시하고 편집연산들의 실행 효과의 분석을 통해 트리 구조 문서에 대한 인접한 편집연산들의 순서 교환 방법을 제안한다. 트리 구조 문서에 대한 변화탐지의 결과로 생성되는 편집스크립트들은 대부분 기본연산들(갱신, 삽입, 삭제)만으로 구성된다. 그러나 이동, 복사연산을 포함하는 경우, 이들의 복합연산의 특성으로 인해 주로 2단계 패스의 실행을 전제로 하는 편집스크립트를 생성한다. 본 논문에서는 제안한 편집 연산들의 순서 교환 방법을 통해 2단계 패스의 실행을 전제로 하는 X-treeESgen의 편집스크립트를 단일 패스로 변환하는 알고리즘을 제시한다.

• 한국정보시스템학회지:정보시스템연구
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• 제5권
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• pp.149-173
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• 1996

This paper focus on the development of object-oriented model bases for Structured Modeling. For the model base organization, object modeling techniques and model typing concept which is similar to data typing concept are used. Structured modeling formalizes the notion of a definitional system as a way of dscribing models. From the object-oriented concept, a structured model can be represented as follows. Each group of similar elements(genus) is represented by a composite class. Other type of genera can be represented in a similar manner. This hierarchical class composition gives rise to an acyclic class-composition graph which corresponds with the genus graph of structured model. Nodes in this graph are instantiated to represent the elemental graph for a specific model. Taking this class composition process one step further, we aggregate the classes into higher-level composite classes which would correspond to the structured modeling notion of a module. Finally, the model itself is then represented by a composite class having attributes each of whose domain is a composite class representing one of the modules. The resulting class-composition graph represent the modular tree of the structured.

• 한국국방경영분석학회지
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• 제28권2호
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• pp.34-55
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• 2002

This paper deals with the multiple attribute decision making problem when a decision maker incompletely articulates his/her preferences about the attribute weight and alternative value. Furthermore, we consider the attribute tree which is structured hierarchically. Techniques for establishing dominance with linear partial information are proposed in a hierarchically structured attribute tree. The linear additive value function under certainty is used in the model. The incompletely specified information constructs a feasible region of linear constraints and therefore the pairwise dominance relationship between alternatives leads to intractable non-linear programming. Hence, we propose solution techniques to handle this difficulty. Also, to handle the tree structure, we break down the attribute tree into sub-trees. Due to there cursive structure of the solution technique, the optimization results from sub-trees can be utilized in computing the value interval on the topmost attribute. The value intervals computed by the proposed solution techniques can be used to establishing the pairwise dominance relation between alternatives. In this paper, pairwise dominance relation will be represented as strict dominance and weak dominance, which ware already defined in earlier researches.

• Journal of the Korean Statistical Society
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• 제25권1호
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• pp.1-24
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• 1996

In selecting a final tree, Breiman, Friedman, Olshen, and Stone(1984) compare the prediction risks of a pair of tree, where one contains the other, using the standard error of the prediction risk of the larger one. This paper proposes an approach to selection of a final tree by using the standard error of the difference of the prediction risks between a pair of trees rather than the standard error of the larger one. This approach is compared with CART's for simulated data from a simple regression model. Asymptotic results of the approaches are also derived and compared to each other. Both the asymptotic and the simulation results indicate that final trees by CART tend to be smaller than desired.

• Communications for Statistical Applications and Methods
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• 제19권2호
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• pp.293-301
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• 2012

Quantile regression proposed by Koenker and Bassett (1978) is a statistical technique that estimates conditional quantiles. The advantage of using quantile regression is the robustness in response to large outliers compared to ordinary least squares(OLS) regression. A regression tree approach has been applied to OLS problems to fit flexible models. Loh (2002) proposed the GUIDE algorithm that has a negligible selection bias and relatively low computational cost. Quantile regression can be regarded as an analogue of OLS, therefore it can also be applied to GUIDE regression tree method. Chaudhuri and Loh (2002) proposed a nonparametric quantile regression method that blends key features of piecewise polynomial quantile regression and tree-structured regression based on adaptive recursive partitioning. Lee and Lee (2006) investigated wage determinants in the Korean labor market using the Korean Labor and Income Panel Study(KLIPS). Following Lee and Lee, we fit three kinds of quantile regression tree models to KLIPS data with respect to the quantiles, 0.05, 0.2, 0.5, 0.8, and 0.95. Among the three models, multiple linear piecewise quantile regression model forms the shortest tree structure, while the piecewise constant quantile regression model has a deeper tree structure with more terminal nodes in general. Age, gender, marriage status, and education seem to be the determinants of the wage level throughout the quantiles; in addition, education experience appears as the important determinant of the wage level in the highly paid group.

• 한국컴퓨터정보학회논문지
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• 제9권4호
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• pp.27-32
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• 2004

XML 문서가 DTD를 포함하지 않거나 여러 곳에서 XML문서를 모았을 때, 그 구조는 비정규적일 수 있다. 비정규적인 구조를 가지는 문서들에 대해 정확한 구조적 질의를 작성하는 것은 어려운 일이다. 이 논문에서는 XML 문서의 효율적인 관리와 검색을 위한 XML 문서 모델과 구조적 검색 방법을 제안한다. 이를 위해 XML 문서의 구조 정보를 표현하기 위해 엘리먼트에 대한 정보를 갖는 고정된 크기의 LETID를 사용하고, 구조 정보 검색을 위한 부모 및 자식 엘리먼트 검색 알고리즘을 제시하였다. 제안된 방법을 이용하여 XML 문서의 구조 정보를 효율적으로 표현할 수 있을 뿐만 아니라. 간단한 연산으로 특정 엘리먼트에 직접적인 접근과 다양한 질의 처리가 가능하다. 또한, 특정 엘리먼트의 부모. 자식, 형제에 대한 다양한 구조 검색을 효율적으로 지원할 수 있는 효과가 기대된다.

• Journal of the Korean Data and Information Science Society
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• 제25권5호
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• pp.1137-1149
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• 2014

Since the bifurcating autoregressive (BAR) model was developed by Cowan and Staudte (1986) to analyze cell lineage data, a lot of research has been directed to BAR and its generalizations. Based mainly on the author's works, this paper is concerned with a contemporary review on the BAR in terms of an overview and perspectives. Specifically, bifurcating structure is extended to multi-cast tree and to branching tree structure. The AR(1) time series model of Cowan and Staudte (1986) is generalized to tree structured random processes. Branching correlations between individuals sharing the same parent are introduced and discussed. Various methods for estimating parameters and related asymptotics are also reviewed. Consequently, the paper aims to give a contemporary overview on the BAR model, providing some perspectives to the future works in this area.

• 대한간호학회지
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• 제36권4호
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• pp.662-670
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• 2006

Purpose. This study was performed to develop and test a decision-tree model of treatment-seeking behaviors about when Korean patients visit a doctor after experiencing stroke symptoms. Methods. The study used methodological triangulation. The model was developed based on qualitative data collected from in-depth interviews with 18 stroke patients. The model was tested using quantitative data collected from interviews and a structured questionnaire involving 150 stroke patients. The predictability of the decision-tree model was quantified as the proportion of participants who followed the pathway predicted by the model. Results. Decision outcomes of the model were categorized into immediate and delayed treatment-seeking behavior. The model was influenced by lowered consciousness, social-group influences, perceived seriousness of symptoms, past history of hypertension or stroke, and barriers to hospital visits. The predictability of the model was found to be 90.7%. Conclusions. The results from this study can help healthcare personnel understand the education needs of stroke patients regarding treatment-seeking behaviors, and hence aid in the development of educational strategies for stroke patients.

• Wind and Structures
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• 제22권1호
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• pp.89-106
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• 2016

With an aim to assess the wind damage to urban trees in more realistic conditions, the nonlinear dynamics of structured trees subjected to strong winds with different levels is investigated in the present paper. For the logical treatment of dynamical behavior of trees, material nonlinearities of green wood associated with tree biomechanics and geometric nonlinearity of tree configuration are included. Applying simulated fluctuating wind velocity to the numerical model, the dynamical behavior of the structured tree is explored. A comparative study against the linear dynamics analysis usually involved in the previous researches is carried out. The failure wind velocity of urban trees is then defined, whereby the failure percentages of the tree components are exposed. Numerical investigations reveal that the nonlinear dynamics analysis of urban trees results in a more accurate solution of wind-induced response than the classical linear dynamics analysis, where the nonlinear effect of the tree behavior gives rise to be strengthened as increasing of the levels of wind velocity, i.e., the amplitude of 10-min mean wind velocity. The study of relationship between the failure percentage and the failure wind velocity provides a new perspective towards the vulnerability assessment of urban trees likely to fail due to wind actions, which is potential to link with the practical engineering.