• 한국자동차공학회논문집
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• 제10권1호
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• pp.59-66
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• 2002

This paper presents the process of the needle lift estimation ova common-rail injector fur HSDI(High Speed Direct Injection) diesel engines. A nonlinear mathematical model of dynamic behaviors of common-rail injector is established at first. Based on the mathematical model of the common-rail injector, the methodology of estimating the injector needle lift is introduced. A sliding mode observer is applied to overcome the model uncertainties. The common-rail injector model and the needle lift estimator are verified by simulations and experiments. The simulation and experimental results indicate that the model outputs are in a good agreement with experimental data, and the proposed nonlinear sliding observer can effectively estimate the needle lift.

• 한국컴퓨터정보학회논문지
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• 제21권5호
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• pp.57-64
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• 2016

In this paper, we propose the design of railway safety common data model to provide common transformation method for collecting data from railway facility fields to Real-time railway safety monitoring and control system. This common data model is divided into five abstract sub-models according to the characteristics of data such as 'StateInfoMessage', 'ControlMessage', 'RequestMessage', 'ResponseMessage' and 'ExtendedXXXMessage'. This kind of model structure allows diverse heterogeneous data acquisitions and its common conversion method to DDS (Data Distribution Service) format to share data to the sub-systems of Real-time railway safety monitoring and control system. This paper contains the design of common data model and its DDS Topic expression for DDS communication, and presents two kinds of data transformation case studied for verification of the model design.

• 한국자동차공학회논문집
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• 제11권5호
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• pp.43-49
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• 2003

The common-rail fuel injection system is becoming a common technology for High Speed Direct Injection(HSDI) diesel engines. The injection timing and rate are important factors for combustion control and pollutants formation mechanisms during engine operation. This paper introduces an estimation methodology of the injection timing and rate of a common-rail injector for HSDI diesel engines. A sliding mode observer that is based on the nonlinear mathematical model of the common-rail injector is designed to overcome the model uncertainties. The injector model and the estimator we verified by relevant injection experiments in an injector test bench. The simulation and the experimental results show that the proposed sliding mode observer can effectively estimate the injection rate of the common-rail injector.

• 한국항공우주학회지
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• 제49권3호
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• pp.167-174
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• 2021

NASA Common Research Model의 29.7% 축소 모형에 대하여 저속 풍동시험 조건으로 수치해석을 수행하였다. 낮은 레이놀즈수 영역인 0.3×106에서 Belly sting 모형 지지부를 장착한 CRM의 공력계수를 측정하는 시험이 수행되었으며, 수치해석 결과와 비교하였다. 해석의 타당성을 검증하기 위해 선행연구 조건으로 전산해석을 수행하여 비교하였다. Belly sting 모형 지지부 유무에 대한 해석 결과 지지부에 의한 간섭 효과로 동체뿐만 아니라 주날개, 꼬리날개까지 공력에 영향이 있음을 확인하였다.

• 한국영재학회:학술대회논문집
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• 한국영재학회 2005년도 춘계학술대회
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• pp.173-180
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• 2005

The purpose of this study was to identify common and domain-specific cognitive characteristics of gifted students based on a hierarchical structural model of human abilities. This study is based on the premise that abilities identified by tests can appear as observable characteristics in test or school situations. Abilities proposed by major models of intelligence were reviewed in terms of their power to explain cognitive characteristics of gifted students. However, due to the lack of their explanatory power and disagreement on common and domain-specific cognitive abilities, a new hierarchical structural model was conceptualized in a unique way based on interrelationships between abilities proposed by the models. The newly established model hypothesizes a cognitive mechanism that accounts for how domain-specific knowledge is formed, as well as which abilities are common and domain-specific, how they are related functionally, and how they account for common and domain-specific cognitive characteristics of gifted students. The cognitive mechanism has important implications for our understanding of the chronically controversial concepts, 'intelligence' and 'knowledge.' Clearer definitions of what intelligence is (g or multiple), what knowledge is, and how knowledge develops ('genetic or environmental,' 'rationalistic or empiricist') may result from this model.

• 한국지능시스템학회논문지
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• 제27권1호
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• pp.7-14
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• 2017

이론적으로 분산 비동기 통신 환경에서 공통믿음 또는 공통지식의 형성은 불가능하다고 받아들여져 왔으나, 서로 신뢰하는 에이전트 그룹에서는 비동기 통신을 사용하더라도 데드라인이 있는 명제들은 공통믿음이 될 수 있고 이를 바탕으로 한 추론이 가능함을 보여준다. 일반적으로 멀티에이전트 환경에서 공통믿음의 형성은 통신의 문제로 접근하며 통신 시간의 제약이 없는 시스템 상에서는 공통믿음이 형성되지 않는다는 공통믿음 역설 문제를 느슨한 정밀도를 적용하고 필요한 요구조건을 완화시켜 공통믿음을 형성 할 수 있음을 카카오톡 채팅방 모델을 통해 확인한다. 또한 카카오톡 채팅방 모델의 각 에이전트에 추론 기능을 구현하여 생성된 공통믿음을 알고 있는지에 관한 질의를 통해 공통믿음임을 확인하는 추론 기능을 실험하였다. 분산 멀티에이전트 환경에서 공통믿음의 표현과 추론을 메타논리 프로그래밍으로 형식화하였으며, 카카오톡 채팅방 모델을 통해 비동기 통신을 사용하는 분산 에이전트 그룹이 공통믿음을 형성할 수 있음을 실험적으로 보였다.

• 정보보호학회논문지
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• 제13권5호
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• pp.57-67
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• 2003

보안정책모델은 평가대상제품(Target of Evaluation, TOE)의 보안정책을 비정형적, 준정형적, 또는 정형적 방법을 사용하여 구조적으로 표현하는 한 것이다. 보안정책모델은 보안기능요구사항과 기능명세간의 일관성 및 완전성을 제공함으로써 평가대상제품이 요구사항과 기능명세간 불명확성으로 인한 보안결점을 최소화할 수 있도록 보증성을 보장한다. 이러한 이유로 ISO/IEC 15408(공통평가기준. CC) 등 IT 제품 및 시스템의 보안성 평가기준의 고등급 평가에서 보안정책모델을 요구하고 있다. 본 논문에서는 보안정책모델의 개념과 관련 연구 및 공통평가기준의 보안정책모델 보증요구사항을 분석하여 보안정책모델 평가방법을 제시한다.

• Communications for Statistical Applications and Methods
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• 제22권5호
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• pp.415-434
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• 2015

In this paper we overview the literature on common features analysis of economic time series. Starting from the seminal contributions by Engle and Kozicki (1993) and Vahid and Engle (1993), we present and discuss the various notions that have been proposed to detect and model common cyclical features in macroeconometrics. In particular, we analyze in details the link between common cyclical features and the reduced-rank regression model. We also illustrate similarities and differences between the common features methodology and other popular types of multivariate time series modelling. Finally, we discuss some recent developments in this area, such as the implications of common features for univariate time series models and the analysis of common autocorrelation in medium-large dimensional systems.

• 한국주거학회논문집
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• 제25권4호
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• pp.125-133
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• 2014

The purpose of this study was to find the role of participation in common activities and satisfaction with common space in a tentative housing adjustment framework for Swedish cohousing residents, applying the housing adjustment behavior model of Morris and Winter (1978, 1996). The data used for this research were a subset of data Choi and Paulsson (2011) surveyed from 12 Swedish cohousing units. Number of 216 cases whose age was 40 and over were selected and analyzed with Pearson correlations and hierarchical linear regressions by SPSS. The regression analyses included four main concepts as endogenous variables, which were participation in common activities, satisfaction with common space, overall life satisfaction, and intention to move out. The results showed that participation in common activities raised satisfaction with common space and overall life satisfaction but reduced intention to move out. Meanwhile, satisfaction with common space diminished intention to move out but did not impact overall life satisfaction. When overall life satisfaction was added to the final regression model, the direct impacts of security reasons, participation in common activities, and satisfaction with common space on intention to move out disappeared. It may be concluded that participation in common activities and satisfaction with common space acted as intervening variables in the tentative cohousing adjustment framework. Even though this study leaves further research on specifying the framework, it may be noteworthy as a first attempt that explains the flow of main concepts. This study may broaden the possibility of empirical studies to develop an analytical path model of housing adjustment for cohousing residents.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2331-2333
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• 2002

In this paper, we propose a new model with the common Control Rod Control System which can be applied to both Korea Standard Nuclear Power Plant model and Westinghouse model. The common model classified by one control rod assembly can solve the common-mode failure. We digitalize the new model and make existing analog models simplified.